JPH1036799A - Adhesive for vinyl chloride resin - Google Patents

Abstract

(57) [Summary] [Problem] Even when acrylonitrile is used, by controlling the gel content of the copolymer to a certain value or less, excellent peel adhesive strength, tensile shear strength, initial adhesive strength, etc. are obtained. Provided is an adhesive for a vinyl chloride resin having excellent adhesive properties, such as excellent plasticizer resistance to a plasticizer contained in a base material made of the resin and compatibility with a vinyl chloride resin, and the like. SOLUTION: Acrylonitrile 25% by weight or more, 45% by weight
% By weight, 45% by weight or more of conjugated diene monomer, 74% by weight
% By weight, 1% by weight or more and 10% by weight or less of an ethylenically unsaturated carboxylic acid monomer and 20% by weight or less of other monomers copolymerizable therewith (total 100% by weight) ) Obtained by emulsion polymerization, the number average molecular weight is 100,000 or more and 500,000 or less, and the gel content is 50% by weight.
An adhesive for a vinyl chloride-based resin, comprising the following copolymer latex and a tackifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for vinyl chloride resin.

[0002]

2. Description of the Related Art Vinyl chloride resin base materials are widely used as flooring materials, for example, because they can be easily applied, and colors and designs can be freely selected. As an adhesive for a substrate made of a vinyl chloride resin, a solvent-type chloroprene adhesive has been generally used. However, solvent-based adhesives use a large amount of an organic solvent, and thus pose problems such as a danger of fire and organic solvent poisoning, and may cause environmental pollution.

As an alternative to such a solvent-based adhesive, there is a method using an aqueous adhesive such as a chloroprene latex, an acrylic emulsion, or an SBR latex, which does not have the above-mentioned problems. However, chloroprene latex has a large decrease in pH over time due to free chlorine,
There is a problem that the stability after prescription is poor and the initial tack is poorly expressed. In an acrylic emulsion, the appearance of tack is affected by temperature, and rubber elasticity is insufficient. SBR latex has the disadvantage that it has poor adhesive strength and the plasticizer easily migrates.

[0004] As a method of improving the problem of such an aqueous adhesive, a vinyl chloride-based resin containing a latex obtained by copolymerizing methacrylonitrile, a conjugated diene and an ethylenically unsaturated carboxylic acid and a tackifier is used. An adhesive for resin is known (JP-A-3-26775). However, in this adhesive, it is necessary to use a latex obtained by copolymerizing a large amount of methacrylonitrile,
Also, when acrylonitrile is used instead of methacrylonitrile, the peel adhesion decreases.

[0005]

The inventors of the present invention have conducted intensive studies to develop adhesives having excellent adhesive strength to various vinyl chloride resins, and have found that copolymer gels can be obtained using acrylonitrile. By controlling the content to a certain value or less, it has been found that an adhesive having excellent peel adhesion can be obtained. In addition, this adhesive is excellent in tensile shear strength and initial adhesive strength, and also has excellent plasticizer resistance to plasticizer contained in the base material made of vinyl chloride resin and compatibility with vinyl chloride resin. And thus have a well-balanced adhesive property. The present invention has been made based on such findings.

[0006]

That is, the present invention relates to an acrylonitrile of 25% by weight or more and 45% by weight or less, a conjugated diene monomer of 45% by weight or more and 74% by weight or less, 1% by weight or more and 10% by weight or less and other monomers copolymerizable therewith
A copolymer latex having a number average molecular weight of 100,000 or more and 500,000 or less and a gel content of 50% by weight or less, obtained by emulsion polymerization of a monomer mixture consisting of 0% by weight or less (100% by weight in total). And a tackifier.

The copolymer latex used in the present invention comprises:
It is obtained by emulsion polymerization of a monomer mixture comprising acrylonitrile, a conjugated diene monomer, an ethylenically unsaturated carboxylic acid monomer and other monomers copolymerizable therewith.

Acrylonitrile is used in an amount of 25% by weight or more and 45% by weight or less, preferably 30% by weight or less, of all monomers.
% By weight or more and 35% by weight or less. If it is less than 25% by weight, the adhesive strength is poor, and the plasticizer resistance to the plasticizer contained in the base material made of the vinyl chloride resin and the conformability to the vinyl chloride resin are poor. Conversely, if it exceeds 45% by weight, the polymerization does not easily proceed.

The conjugated diene monomers include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-
Examples thereof include pentadiene and chloroprene. Among these conjugated diene monomers, 1,3-butadiene is preferred. The amount of the conjugated diene-based monomer used is 45% by weight or more and 74% by weight or less, preferably 55% by weight or more and 65% by weight or less of all the monomers. 45% by weight
If it is less than 1, polymerization does not easily proceed. Conversely, if it exceeds 74% by weight, the adhesive strength is poor, and the plasticizer resistance to the plasticizer contained in the vinyl chloride resin base material and the compatibility with the vinyl chloride resin are poor.

Examples of the ethylenically unsaturated carboxylic acid monomer include: monocarboxylic acids such as (meth) acrylic acid; polycarboxylic acids such as itaconic acid, fumaric acid and maleic acid; polycarboxylic acids such as monomethyl maleate Partial esters and the like can be mentioned. Of these ethylenically unsaturated carboxylic acid monomers, monocarboxylic acids are preferred. The amount of the ethylenically unsaturated carboxylic acid monomer used is 1% by weight or more and 10% by weight or less, preferably 2% by weight or more and 8% by weight or less based on all the monomers. This amount is 1% by weight
When it is less than 10%, the adhesive strength is inferior, and when it exceeds 10% by weight, the copolymer latex tends to thicken with the passage of days.

Other copolymerizable monomers include aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, hydroxymethylstyrene, divinylbenzene and vinyltoluene; methyl (meth) acrylate; Ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate,
Examples include ethylenically unsaturated carboxylic esters such as hydroxypropyl (meth) acrylate, glycidyl methacrylate, dimethyl phthalate, and diethyl fumarate; and amide compounds such as acrylamide, methacrylamide, and N-methylolacrylamide. The amount of the other copolymerizable monomer used is within a range of 20% by weight or less based on all the monomers for obtaining the copolymer latex. Also, methacrylonitrile can be used if it is less than 10% by weight.

Examples of the method for producing the copolymer latex of the present invention include known emulsion polymerization methods such as continuous emulsion polymerization, batch emulsion polymerization, two-stage emulsion polymerization, and division addition polymerization. The polymerization temperature varies depending on the molecular weight of the target copolymer latex, the gel content, and the like, and cannot be specified unconditionally, but is usually 0 to 25 ° C, preferably 5 to 15 ° C. In the emulsion polymerization, a known emulsifier, a chain transfer agent,
Additives and auxiliaries used in general emulsion polymerization, such as a polymerization initiator and a chelating agent, can be used.

Examples of the emulsifier include higher alcohol sulfates, alkylbenzene sulfonates, alkyl diphenyl ether sulfonates, aliphatic sulfonates,
Anionic surfactants such as aliphatic carboxylate salts; nonionic surfactants such as polyethylene glycol alkyl ester type, alkyl phenyl ether type and alkyl ether type surfactants can be used. These are 2
A combination of more than one species may be used.

Examples of the chain transfer agent include mercaptan compounds such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan; thioglycolic acid, 2-ethylhexyl Thioglycols such as thioglycolate; Xanthogen compounds such as dimethyl xanthogen disulfide, diethylxanthogen disulfide, dipropylxanthogen disulfide; α-methylstyrene dimer; terpinolene; tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram mono Thiuram compounds such as sulfides; allyl compounds such as allyl alcohol, acrolein and methacrolein; Phenolic compounds such as di-t-butyl-4-methylphenol and styrenated phenol; halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, carbon tetrachloride and carbon tetrabromide; triphenylethane and pentaphenylethane And polyphenyl compounds. These may be used in combination of two or more.

Examples of the initiator include persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; peroxides such as benzoyl peroxide; and redox initiators comprising an oxidizing agent and a reducing agent. Among them, redox initiators are awarded. Examples of the oxidizing agent for the redox initiator include diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide and the like. Organic peroxides; hydrogen peroxide and the like are used, and as a reducing agent, compounds of metals in a reduced state such as ferrous sulfate and cuprous naphthenate; sulfonic acids such as methanesulfonic acid; dimethylaniline and the like Amines: Sodium salts or potassium salts of acids such as ethylenediaminetetraacetic acid, formic acid, citric acid, and pyrophosphoric acid are used.

The copolymer latex used in the present invention has a number average molecular weight of 100,000 or more, preferably 150,000 or more, as measured by gel permeation chromatography using THF (tetrahydrofuran) as an eluent. 500,000 or less, preferably 200,000 or more, 4
Less than 100,000. When the number average molecular weight is less than 100,000, the adhesive strength of the adhesive is inferior, and when it is 500,000 or more, the initial adhesive strength is reduced.

The gel content of the copolymer latex used in the present invention is 50% by weight or less, preferably 30% by weight or less. In the present invention, it is important that the gel content of the copolymer latex is in the above range, and if it exceeds 50% by weight, the adhesion is poor, and the compatibility with the tackifier is poor. Poor plasticizer resistance to the plasticizer contained in the base material made of vinyl chloride resin, and poor compatibility with vinyl chloride resin. In addition, the gel content referred to in the present invention is determined by the method described in Examples below.

The molecular weight and the amount of gel can be controlled by the polymerization temperature, the amount of a molecular weight modifier added, the type of polymerization initiator, the conversion at the time of stopping the reaction, and the like.

The tackifier has a softening point of 80 to 15.
0 ℃ rosin or modified rosin, C ₅ petroleum resins, C ₉ petroleum resins, phenol-modified C ₉ petroleum resin, C ₅ · C ₉ copolymer resin, terpene resin, terpene phenol resin, alkylphenol resin, coumarone resin, etc. Known tackifiers are used. These tackifiers are used alone or in combination of two or more.

The amount of the tackifier in the adhesive for vinyl chloride resin of the present invention is determined based on the copolymer latex (solid content)
The amount is usually 50 to 200 parts by weight, preferably 70 to 150 parts by weight, per 100 parts by weight. The B-type viscosity of the tackifier is
Usually measured as 70% by weight toluene solution, 4,
Preferably, it is between 000 and 8,000 millipascal seconds. The B-type viscosity was measured using a rotor N with a BH-type viscometer.
o. 6 using a rotation speed of 10 RPM × 60 seconds at 20 ° C.

In the present invention, in addition to the copolymer latex and the tackifier, as long as the effects of the present invention are not impaired,
Plasticizers such as process oils, fillers such as calcium carbonate and clay, defoamers, preservatives, antioxidants, thickeners, and the like can be appropriately compounded. The amount of the filler is 500 parts by weight or less based on 100 parts by weight of the copolymer latex (solid content).

The B-type viscosity of the adhesive of the present invention is from 50,000 to
Preferably, it is 80,000 millipascal seconds.

[0023]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. In the examples, parts and% are based on weight, and latex is calculated as solid content.

The physical properties of the copolymer latex and the evaluation of the adhesive were determined according to the following methods. (Gel Content) After adjusting the pH of the copolymer latex to 8.5, it was cast on a glass plate in an atmosphere of 20 ° C. and a relative humidity of 65%, and dried for 72 hours to form a film. 0.2 grams of this film is accurately weighed and
Immersed in 100 ml of methyl ethyl ketone at
After standing for 48 hours, the mixture was filtered through a previously weighed 80-mesh wire net, and the residue remaining on the wire net was weighed. The residue was dried at 100 ° C., its weight was determined, and the gel content was determined by the following equation.

(Equation 1)

(Tensile shearing force) The tensile shearing force was measured according to the test method of JIS K 6851. Plywood (thickness 3mm, width 25 ±
0.5 mm, length 100 ± 0.5 mm) [(2
(5 ± 0.5 mm) × (25 ± 0.5 mm)] is uniformly coated with the adhesive of Example (100 g / m ² ) (coating thickness: 0.1 mm), the bonding surfaces are combined, and the temperature and humidity chamber ( 20 ± 2
(° C, relative humidity 60 ± 5%) for 7 days to prepare a test piece. The tensile shearing force was measured using a universal material testing machine, Tensilon UTM-10T, and the tensile moving speed in the longitudinal direction was 1.
The measurement was performed at 0 mm / min. The maximum load until the test piece was broken was measured, the maximum load was divided by the shear area, and the tensile shear force (N / mm ² ) was determined.

(Peeling Adhesion) The peeling adhesion was measured according to the test method of JIS A 5536. PVC resin sheet (width 25
± 0.5 mm, length 200 ± 0.5 mm)
5 mm × 150 mm] is uniformly coated with the adhesive of the example (100 g / m ² ) (coating thickness: 0.1 mm), the bonding surfaces are combined, and the temperature and humidity chamber (20 ± 2 ° C., relative humidity 60 ± 5) is applied.
%) For 7 days to prepare a test piece. The peel adhesion was measured using a universal material testing machine, Tensilon UTM-10T, at a tensile movement speed of 200 ± 20 mm / min in the longitudinal direction, and the 90 ° peel adhesion was measured.

(Initial adhesive strength) The initial adhesive strength was measured according to the test method of JIS A 5536. PVC resin sheet (width 25
± 0.5 mm, length 200 ± 0.5 mm)
5 mm x 150 mm], apply evenly 100 g / m ² of the adhesive of the example (applied thickness: 0.1 mm), leave for 20 minutes, align the adhesive surfaces, press and cure, and cure for 5 minutes to prepare a test piece did. The measurement of the initial adhesive force was performed in the same manner as the measurement of the peel adhesive force.

(Plasticizer resistance) It was carried out according to the test method of JIS A 5536. PVC resin sheet (width 25
± 0.5 mm, length 200 ± 0.5 mm)
5 mm × 150 mm] is uniformly coated with the adhesive of the example (100 g / m ² ) (coating thickness: 0.1 mm), the bonding surfaces are combined, and the temperature and humidity chamber (20 ± 2 ° C., relative humidity 60 ± 5) is applied.
%) And cured for 2 months in a dryer at 60 ° C. Further, the specimen was left standing at a constant temperature and humidity for one day to prepare a test piece. The evaluation of the plasticizer resistance was performed in the same manner as the measurement of the peel adhesion.

(Familiarity) In the peeling test, the destruction state of the bonded portion was visually observed. Only cohesive failure was observed.両 方 Both cohesive failure and interfacial failure were observed. △

Reference Example Production of Copolymer Latex Monomer 100 having the composition shown in Tables 1-2 in a tank equipped with a stirrer
, 0.5 part of sodium lauryl sulfate, 0.4 part of t-dodecyl mercaptan and 150 parts of water, to prepare a monomer emulsion. On the other hand, in an autoclave equipped with a stirrer, 0.5 part of sodium lauryl sulfate, 0.05 part of diisopropylbenzene hydroperoxide, 0.02 part of ethylenediaminetetraacetic acid sodium salt, 0.03 part of potassium pyrophosphate, 0.003 part of frost iron, 0.03 part of sodium formaldehyde sulfoxylate and 50 of water
Then, polymerization was carried out at 5 ° C. for 20 hours to obtain a copolymer latex. The polymerization conversion of each of the copolymer latexes was 95% or more. The number average molecular weight and gel content of each of the obtained copolymer latexes were measured, and the copolymer latexes satisfying the requirements of the present invention are shown in Table 1, and the copolymer latexes not satisfying the requirements of the present invention are shown in Table 1. 2 is shown.

[0031]

[Table 1]

[0032]

[Table 2]

Example 1 / Comparative Example 1 Preparation and Evaluation of Adhesive for Vinyl Chloride Resin Using each copolymer latex obtained in Reference Example, an adhesive having a solid content of 70% was obtained according to the following composition. . The adhesive strength and the like of the adhesive were evaluated, and the results are shown in Tables 3 and 4. [Blending] Copolymer latex (solid content) 100 parts Phenol-modified C ₉ resin * 1 90.5 parts Calcium carbonate * 2 301.7 parts Thickener * 3 8 parts * 1; trade name, manufactured by Toho Chemical Co., Ltd. 70% of Pm-70
B-type viscosity measured in a toluene solution of 6,000
It is in millipascal seconds. * 2: Nitto Powder Co., Ltd., trade name NS-100 * 3: Rohm and Haas Co., Ltd., trade name RM-5

[0034]

[Table 3]

[0035]

[Table 4]

Example 2 Using the copolymer latex (a) as the copolymer latex and the tackifier shown in Table 5, an adhesive having a solid content of 70% was obtained according to the above composition. The adhesive strength of the adhesive was evaluated. The following tackifiers were used in Table 5. C ₅ · C ₉ copolymer resin; manufactured by Toho Chemical Co., Ltd., trade name High Resin # 60, B type viscosity 6,000 millipascal second rosin ester; manufactured by Arakawa Chemical Co., Ltd., trade name ester gum, B type viscosity 6,000 Millipascal second rosin phenol resin; manufactured by Arakawa Chemical Co., Ltd., trade name: Tamanol 135, B type viscosity: 6,000 millipascal seconds Terpene phenol resin; manufactured by Arakawa Chemical Co., Ltd., trade name: Tamanol 803L, B type viscosity: 6,000 millipascal Second

[0037]

[Table 5]

The embodiments of the present invention are listed below. 1. Acrylonitrile 25 wt% or more, 45 wt% or less, conjugated diene monomer 45 wt% or more, 74 wt% or less, ethylenically unsaturated carboxylic acid monomer 1 wt% or more,
10% by weight or less, and a monomer mixture composed of 20% by weight or less of other monomers copolymerizable therewith (total 10%).
0% by weight), and having a number average molecular weight of 1
An adhesive for a vinyl chloride resin, comprising: a copolymer latex having a gel content of not less than 100,000 and not more than 500,000, and a tackifier of not more than 50% by weight. 2. 2. The adhesive for a vinyl chloride resin according to the above item 1, which has a 90 ° peel force (N / 25 mm width) of 30 or more and a plasticizer resistance (N / 25 mm width) of 20 or more. 3. 3. The adhesive for a vinyl chloride resin according to the above 1 or 2, which has a tensile shear force (N / mm ² ) of 4.0 or more. 4. 4. The adhesive for a vinyl chloride-based resin according to the above 1, 2, or 3, which has an initial adhesive strength (N / 25 mm width) of 20 or more. 5. 5. The adhesive for a vinyl chloride-based resin according to the above 1, 2, 3, or 4, wherein the B-type viscosity is 50,000 to 80,000 millipascal seconds.

[0039]

The adhesive for vinyl chloride resin of the present invention thus obtained is excellent in adhesive strength such as peel adhesive strength, tensile shear strength and initial adhesive strength. In addition, plasticizers eluted from the vinyl chloride resin base material generally tend to reduce the adhesive strength of the adhesive, but the adhesive of the present invention does not show a decrease in the adhesive due to the plasticizer. Excellent agent properties.

Claims (1)

[Claims] 1. An acrylonitrile content of at least 25% by weight,
% By weight, 45% by weight or more of conjugated diene monomer, 74% by weight
% By weight, 1% by weight or more and 10% by weight or less of an ethylenically unsaturated carboxylic acid monomer, and 20% by weight or less of other monomers copolymerizable therewith (total 100% by weight) A) a copolymer latex having a number average molecular weight of 100,000 or more and 500,000 or less and a gel content of 50% by weight or less, obtained by emulsion polymerization of Adhesive for resin.