JP2000086821A - Polychloroprene latex composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for giving an adhesive, a binder and the like excellent in discoloration resistance to ultraviolet rays of a wavelength not more than a specific nm by combining a phenolic compound to a chloroprene polymer. SOLUTION: A composition is excellent in discoloration resistance to ultraviolet rays of a wavelength not more than 300 nm. Phenols use a phenolic compound (A) having at least one functional group of formula I and/or (B) the phenolic one of formulas II or III. Wherein R1 to R11 are H or a 1-5C alkyl; and n is 1-10. Polychloroprene has preferably 400,000-1,200,000 of the weight- average molecular weight converted into that of polystyrene which is measured by a GPC method, and 3-60% of a gel content. The using amounts of the compounds A and B are preferably 0.05-10 pts.wt. in the solid content to 100 pts.wt. in the solid content of polychloroprene, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polychloroprene latex composition containing a phenolic compound having a specific structure, which can be used for fiber treatment and adhesive products, sterilization use, disinfection use, medical use, etc. 3 used in
The present invention relates to a polychloroprene latex composition excellent in discoloration resistance to ultraviolet light having a wavelength of less than 00 nm, an adhesive, a binder, and the like obtained therefrom.

[0002]

2. Description of the Related Art Hitherto, many studies have been made on improving the discoloration resistance of a polychloroprene latex composition against ultraviolet rays, but these are mainly intended for ultraviolet rays having a wavelength of 300 nm or more. Methods for improving the discoloration resistance of the polychloroprene latex composition against ultraviolet light having a wavelength of 300 nm or more include benzotriazole, triazine, hindered amine, organic nickel, and metal oxide (ultra) fine particles (cerium oxide, oxidized oxide). It is known to add a light stabilizer such as a zinc or titanium oxide type, but these methods improve the discoloration resistance to ultraviolet light having a wavelength of less than 300 nm (hereinafter abbreviated as UV-C). It has little or no effect, if any. Heretofore, there has been no report on a method for improving the discoloration resistance of a polychloroprene latex composition against UV-C.

However, UV-C is often used for sterilization, disinfection, medical use, etc., and UV-C of polychloroprene latex composition used for fiber treatment and adhesive products is used. Discoloration of the toner has been an issue.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the problems of such a polychloroprene latex composition and provides a polychloroprene latex composition for obtaining an adhesive or a binder having excellent resistance to discoloration to UV-C. The purpose is to provide.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, a functional group represented by the following general formula (1) is added to polychloroprene latex in the molecule. Phenolic compounds having at least one compound (Compound A)
By blending one or more and / or one or more phenolic compounds (compound B) having a structure represented by the following general formula (2) or (3), the UV-
The present inventors have found that a polychloroprene latex composition for obtaining an adhesive or a binder having excellent resistance to discoloration to C can be obtained, and have completed the present invention. Heretofore, this particular combination of compounds has never been used for polychloroprene latex.

[0006]

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(Here, R1 and R2 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which may be the same or different from each other, and n represents an integer of 1 to 10.)

[0008]

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(Here, R3 to R11 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which may be the same or different.)

[0010]

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(Here, R3 to R11 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which may be the same or different.)

Hereinafter, the contents of the present invention will be described in detail. The chloroprene polymer contained in the polychloroprene latex in the present invention is a homopolymer of 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer of chloroprene and one or more monomers copolymerizable with chloroprene. It is a copolymer obtained by polymerization.

The monomer copolymerizable with chloroprene in the present invention includes, 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 contained in the polychloroprene latex in the present invention preferably has a polystyrene equivalent weight average molecular weight of from 400,000 to 1.2 million, more preferably from 500,000 to 900,000, as measured by the GPC method. It is preferable that the gel content be 3 to 60%. The polychloroprene latex in the present invention is suitably used for fiber treatment and adhesive products, but has a weight average molecular weight of 400,000 to 1.2 million measured by GPC method and a gel content of 3 to 60%. If so, a polychloroprene latex composition having an excellent balance of processability, adhesiveness and heat resistance can be obtained.

The emulsifier and / or dispersant used for the polychloroprene latex in the present invention is not particularly limited, and various anionic, nonionic and cationic types can be used. Examples of the emulsifier used for the anionic latex include a carboxylic acid type and a sulfate ester type. For example, an alkali metal salt of rosin acid having 8 to 8 carbon atoms is used.
20 alkyl sulfonates, alkyl aryl sulfates, condensates of sodium naphthalene sulfonate and formaldehyde, and the like. Specific examples of the nonionic type include a water-soluble polymer, an ether type, an ester type, a sorbitan ester type, a sorbitan ester ether type, an alkylphenol type, and the like.For example, polyvinyl alcohol and its copolymer, polyoxyethylene tridecyl Examples thereof include ether, polyoxyethylene monostearate, and sorbitan monooleate. Specific examples of the cationic type include aliphatic amine salts,
There are an aliphatic quaternary amine salt, an aromatic quaternary ammonium salt, a heterocyclic quaternary ammonium salt, and the like. Can be

The amount of the emulsifier and / or dispersant used in the polychloroprene latex composition of the present invention is preferably from 1 part by weight to less than 20 parts by weight based on 100 parts by weight of the initially charged chloroprene monomer. . If the amount is less than 1 part by weight, the emulsifying power is insufficient, and if it is more than 20 parts by weight, the adhesive strength is reduced when used as an adhesive composition.

The chloroprene latex composition of the present invention is prepared by adding the compound A and / or the compound B to a chloroprene latex containing the chloroprene polymer obtained by emulsion polymerization according to the method exemplified below. Obtainable. The polymerization method of the chloroprene polymer in the present invention is not particularly limited, a polymerization temperature, a polymerization catalyst, a chain transfer agent, a polymerization terminator,
By properly selecting and controlling the final polymerization rate, demonomerization, concentration conditions, etc., the solid content concentration, the molecular weight of the toluene-soluble part,
It is possible to adjust the gel content and the like.

The polymerization temperature of the chloroprene polymer in the present invention is not particularly limited. 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 the chain transfer agent is not particularly limited, and those usually used for emulsion polymerization of chloroprene can be used, but a xanthate type or a mercaptan type is preferred. The chain transfer agent can be added not only during the preparation but also during the polymerization.

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 is not particularly limited and can be arbitrarily adjusted. Unreacted monomers are removed by a demonomerization operation, but the method is not particularly limited. The obtained polychloroprene latex can be concentrated or diluted by adding water or the like, so that the solid content concentration can be controlled to a necessary concentration. Examples of the method for concentration include concentration under reduced pressure, but are not particularly limited.

The compound A used in the present invention is a phenolic compound having at least one functional group represented by the following general formula (1) in the molecule.

[0023]

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(Wherein R1 and R2 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which may be the same or different, and n represents an integer of 1 to 10). A good example is octadecyl-3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-
t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2 -Thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], isooctyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate, 1- [2- {3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionyloxy {ethyl] -4- {3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionyloxy {-2,
2,6,6-tetramethylpiperidine and the like.

The compound B used in the present invention is a phenolic compound having a structure represented by the following general formula (2) or (3).

[0026]

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(Here, R3 to R11 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, which may be the same or different.)

[0028]

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(Here, R3 to R11 represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and may be the same or different from each other.) As a specific example of the compound B,
4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,2'-methylenebis- (4-methyl-6-t-butylphenol), 2,2'-methylenebis- (4-ethyl-6 -T-butylphenol) and the like. The method of adding and compounding the above compound A and compound B in the present invention is not particularly limited. As the method of addition and blending, there are a method of adding during the polymerization of polychloroprene, a method of adding it as an emulsion or a dispersion to a latex composition, etc. Is preferred.

The amount of the compound A (which may be a mixture of two or more) in the present invention depends on the required performance, but is preferably based on 100 parts by weight of the solid content of the chloroprene polymer. The content is 0.05 to 10 parts by weight in terms of solid content, and more preferably 1 to 5 parts by weight in terms of solid content.
If the solid content exceeds 10 parts by weight, UV-C
Although the discoloration resistance is excellent, storage stability is reduced, and when this latex composition is used as an adhesive composition, the adhesive properties may be reduced,
Not preferred. If the amount is less than 0.05 parts by weight in terms of solid content, sufficient discoloration resistance cannot be obtained.

The amount of the compound B (which may be a mixture of two or more) in the present invention depends on the required performance, but is preferably based on 100 parts by weight of the solid content of the chloroprene polymer. The content is 0.05 to 10 parts by weight in terms of solid content, and more preferably 1 to 5 parts by weight in terms of solid content.
If the solid content exceeds 10 parts by weight, UV-C
Although the discoloration resistance is excellent, storage stability is reduced, and when this latex composition is used as an adhesive composition, the adhesive properties may be reduced,
Not preferred. If the amount is less than 0.05 parts by weight in terms of solid content, sufficient discoloration resistance cannot be obtained. Moreover, the effect becomes more remarkable by using the compound A and the compound B in combination.

In the polychloroprene latex composition of the present invention, the polychloroprene latex and the compound A (a mixture of two or more types) and / or the compound B (a mixture of two or more types may be used). ) Is essential, but a compounding agent usually added to latex, for example, a thickener, a filler, a pH adjuster, a fungicide, a fungicide, an ultraviolet absorber, a tackifier, A sulfurizing agent, a curing agent, and the like can be arbitrarily added.

[0033]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. here,
The discoloration resistance to UV-C was evaluated by the following method. In the following description, the amount of addition and the like are based on weight unless otherwise specified.

[Discoloration Resistance Test for UV-C] The polychloroprene latex composition was applied to blotting paper Shim-1 (trade name, manufactured by KOKUYO Co., Ltd.) with a brush at 200 g / m ^{2, and the} coating was performed at room temperature (23 ° C.). Dry for an hour, UV lamp SD-15A
(Sankyo Electric Co., Ltd., trade name, power consumption 15 W × 2) was used as the irradiation source, and the sample and the light source were set to 10 inches. The change in color tone after irradiation for 4, 8, and 24 hours was examined. The wavelength of the ultraviolet light is 254 nm, and the temperature is 23 ° C. The color tone was measured by a yellowness index using a # 80 color measuring system (trade name, manufactured by Nippon Denshoku Industries Co., Ltd.).

[Solid Content Concentration]
And An aluminum dish containing 2 ml of the latex sample was weighed and designated 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

[Weight average molecular weight of soluble part] GPC measurement was performed under the following conditions. The molecular weight was calculated in terms of polystyrene. The sample was prepared by separating the separated sol with 0.1% by weight of TH.
Adjusted to F solution. Column: PL gel 10 μm GUARD + PL gel 10 μ
mMixed-B x 3 column size: 7.5mmΦ x 50mm (GUAR
D), 7.5 mmΦ × 300 mm (Mixed-B) Column temperature: 35 ° C., solvent: THF, Outflow rate: 1 ml / min Detector: SHIMAZU RID-6A

[Measurement of Gel 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 net. The gel was air-dried and then dried for 1 hour in a 110 ° C. atmosphere. The gel content (%) was calculated according to the following equation. Gel content = (B / A) × 100

The polychloroprene latex was polymerized at a polymerization temperature of 10 ° C. shown in Table 1 under a nitrogen atmosphere while adding a 2% aqueous solution of potassium persulfate as a catalyst. It was prepared using n-dodecyl mercaptan as a serial transfer agent so as to have a solid content of 10% and a solid content of 60% by weight.

The obtained latex was blended according to the formulation shown in Table 1 to obtain latex compositions of Examples 1 to 3 and Comparative Examples 1 and 2. The unit of the compounding amount is the solid content weight.

The compound A was emulsified cellosol F-773 (trade name, manufactured by Chukyo Yushi Co., Ltd.), and the compound B was emulsified cellosol G-9.
69 (manufactured by Chukyo Yushi Co., Ltd., trade name).

The evaluation results of the latex compositions obtained in Examples 1 to 5 and Comparative Example 1 are shown in Table 1.

[0042]

[Table 1]

Examples 6 to 10 and Comparative Example 2 The polychloroprene latex compositions were polymerized at a polymerization temperature of 10 ° C. shown in Table 2 while adding a 2% aqueous solution of potassium persulfate as a catalyst under a nitrogen atmosphere. The n-dodecyl mercaptan was used as a chain transfer agent so as to have a weight average molecular weight of 600,000, a gel content of 10%, and a solid content of 60% by weight.

The resulting latex was blended according to the formulation shown in Table 2 to obtain adhesive compositions of Examples 6 to 10 and Comparative Example 2. The unit of the compounding amount is the solid content weight.

The compound A was emulsified cellosol F-773 (trade name, manufactured by Chukyo Yushi Co., Ltd.), and the compound B was emulsified cellosol G-9.
69 (manufactured by Chukyo Yushi Co., Ltd., trade name).

The evaluation results of the adhesive compositions obtained in Examples 6 to 10 and Comparative Example 2 are shown in Table 2.

[0047]

[Table 2]

As is clear from Table 1 of the Examples, the polychloroprene latex compositions of the present invention (Examples 1 to 5)
Is UV compared to the conventional latex composition (Comparative Example 1)
Excellent resistance to discoloration to -C. As is clear from Table 2 of the Examples, the adhesive compositions using the polychloroprene latex composition of the present invention (Examples 6 to 10) were prepared using the adhesive composition using the conventional latex composition (Comparative Example 2). )
Is excellent in discoloration resistance to UV-C.

[0049]

According to the present invention, as described above, the polychloroprene latex contains at least one phenolic compound having at least one functional group represented by the general formula (1) in the molecule and / or the general formula (2) ) Or by blending at least one phenolic compound having a structure represented by the general formula (3), a polychloroprene latex composition, an adhesive, a binder, and the like having excellent resistance to discoloration to UV-C can be obtained.

Claims (5)

[Claims] 1. A chloroprene polymer and a phenolic compound having at least one functional group represented by the following general formula (1) in a molecule (hereinafter referred to as compound A):
A polychloroprene latex composition comprising at least one kind of phenolic compound having a structure represented by the following general formula (2) or (3) (hereinafter, referred to as compound B). object. Embedded image (Where R1 and R2 are each a hydrogen atom or a C1-5
And may be the same or different from each other. n represents an integer of 1 to 10. ) (Where R3 to R11 are a hydrogen atom or a C1 to C5
And may be the same or different from each other. ) (Where R3 to R11 are a hydrogen atom or a C1 to C5
And may be the same or different from each other. ) 2. The degree of yellowing change ΔYI ((yellowness index of a sample after irradiation) − (yellowness index of a non-irradiated sample)) of less than 60 after 24 hours in a color fastness test for a wavelength of less than 300 nm. The polychloroprene latex composition according to claim 1, wherein: 3. The solid content of polychloroprene latex 1
Compound A is used in an amount of 0.05 to 1 in terms of solid content with respect to 00 parts by weight.
0 parts by weight and / or 0.05% by weight of compound B
The polychloroprene latex composition according to claim 1 or 2, which is contained in an amount of 10 parts by weight. 4. The polychloroprene according to claim 1, wherein the chloroprene polymer has a weight average molecular weight measured by GPC method of 400,000 or more and a gel content of 3 to 60%. Latex composition. 5. An adhesive composition using the polychloroprene latex composition according to any one of claims 1 to 4.