JP2002285122A - Adhesive composition for flooring material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition for a flooring material, having excellent plasticizer resistance and peelability, and suitable for a on-site bonding work of a vinyl chloride resin flooring material. SOLUTION: The adhesive composition for a flooring material contains a copolymer composed of crosslinked acrylic resin particles and having a glass transition temperature of -20 to -60 deg.C and the particles have two particle diameter peaks consisting of (A) a region having particle diameter peak of 50-500 nm and (B) a region having particle diameter peak of 900-2,000 nm. The copolymer is an emulsion produced by the emulsion polymerization of a monomer mixture composed mainly of (meth)acrylic acid alkyl ester monomer and containing 1.0-5.0 wt.% (meth)acrylonitrile and 0.1-5.0 wt.% monomer having >=2 polymerizable vinyl groups in one molecule in an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition for on-site construction of floor materials, and more particularly, to a water-based adhesive composition suitable for on-site construction of floor materials such as soft vinyl chloride resin sheets and tiles containing a plasticizer. The present invention relates to an adhesive composition for flooring.

[0002]

2. Description of the Related Art Solvent-based adhesives have been used in the past for floor construction on site, but there are problems such as work environment, safety for human body, air pollution, fire and explosion, etc.
Water-based adhesives are increasingly used. For example, JP-A-2-38478 discloses an emulsion adhesive composition comprising a conjugated diene rubber latex and a tackifier of a specific composition mixed therein.
No. 657 discloses a glass transition temperature of -20 to +40.
A water-based adhesive composition comprising a polymer emulsion having an average particle diameter of 10 to 500 nm and an elastic body having an average particle diameter of 1 mm or less is disclosed. Further, Japanese Patent Publication No. 9-508662 discloses a dispersion adhesive for floors comprising water, a polymer having a glass transition temperature lower than -25 ° C. and a filler without containing an organic solvent, a plasticizer and an additional adhesive resin. An agent is disclosed. However, when used for flooring made of vinyl chloride resin (hereinafter referred to as PVC flooring), the adhesive film softens and swells due to the migration of the plasticizer contained in the PVC flooring, and the adhesive strength is increased. Problems such as peeling, displacement, and uki due to a decrease in the temperature. Recently, in order to enhance the recyclability of old PVC flooring material that is peeled off during repair or repair, it has been desired that the flooring surface be free of adhesive on the peeling surface. Hereinafter, the property that the adhesive hardly adheres is referred to as releasability.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive for water-based flooring suitable for on-site bonding of PVC flooring having excellent plasticizer resistance and peelability in view of the above problems. To provide an agent composition.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, the acrylic crosslinked particles have the specified composition and glass transition temperature, and further have a particle size The present inventors have found that an adhesive composition for flooring having two particle diameter peak regions having different particle diameters has excellent plasticizer resistance and peelability with respect to PVC flooring, and has completed the present invention.

That is, according to the present invention, the copolymer comprising acrylic crosslinked particles has a glass transition temperature of -20 to -60 ° C.
A floor material adhesive composition having two particle size peaks, a region (A) where the particle size peak of the particles is 50 to 500 nm, and a region (B) where the particle size peak is 900 to 2000 nm, Further, the copolymer composed of the acrylic crosslinked particles contains (meth) acrylic acid alkyl ester monomer as a main component and (meth) acrylonitrile 1.0 to 1
A monomer mixture consisting of 5.0% by weight and 0.1 to 5.0% by weight of a monomer having at least two polymerizable vinyl groups in one molecule (total amount of monomers is 100% by weight) Is a copolymer emulsion obtained by emulsion polymerization in an aqueous medium.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail. The adhesive composition for flooring of the present invention has a copolymer emulsion having two particle diameter peaks having different particle diameters, in order to obtain excellent plasticizer resistance and peelability with respect to PVC flooring. Is essential. The copolymer emulsion in the region where the particle size peak is large, or the copolymer emulsion in the region where the particle size peak is small, and further, the plasticizer resistance and peeling that could not be obtained with the copolymer emulsion having a wide particle size distribution Has a particle diameter peak of 50 to 500 n
(A) region and the particle diameter peak is 900 to 2000 n
m can be obtained by a copolymer emulsion having two particle size peaks in the region (B). This is thought to be due to the presence of two different particle size distributions, whereby the adhesive film formation at room temperature drying becomes a fine state, and the plasticizer resistance and peelability are improved. The particle diameter peak in the (A) region is 50 to 500 nm, preferably 100 to 3 nm.
50 nm. Here, the particle diameter is represented by an average particle diameter, and is expressed by NICOP Model 370 (Particle S
This is a value measured by using the method of izing Systems Inc.).

Further, the ratio of the (A) region where the particle size peak of the copolymer emulsion is 50 to 500 nm and the ratio of the (B) region where the particle size peak is 900 to 2000 nm are in terms of the solid content weight ratio of the (A) region. Is 10 to 40 parts by weight,
(B) the area is 60 to 90 parts by weight, or (A)
It is preferable that the area is 60 to 90 parts by weight and the area (B) is 10 to 40 parts by weight. It is preferable that one of the proportions of the (A) region and the (B) region is large. Outside this range, the releasability decreases.

[0008] The acrylic crosslinked particles of the present invention have a (meth)
It is a copolymer of (meth) acrylonitrile and a monomer having a crosslinkable functional group, mainly composed of an alkyl acrylate monomer, specifically, acrylonitrile or methacrylonitrile, polymerized in one molecule. It is a copolymer obtained by polymerizing a monomer having at least two functional vinyl groups, an alkyl (meth) acrylate monomer, and other copolymerizable monomers.

The (meth) acrylonitrile used in the present invention is necessary not only for improving the plasticizer resistance of the copolymer film but also for improving the releasability. The amount used is 1.0 to 15.0% by weight based on the total amount of the monomers. If the amount used is less than 1.0% by weight, the plasticizer resistance and the releasability will be reduced, and if it is more than 15.0% by weight, the film forming property of the adhesive film will be reduced.

Examples of the monomer having a crosslinkable functional group used in the present invention include N-methylolacrylamide, glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, divinylbenzene and the like. Preferably, it is a monomer having at least two polymerizable vinyl groups in one molecule. Specific examples include divinylbenzene, diallyl phthalate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, and 1,3-propylene glycol di (meth). Acrylate, 1,4-butanediol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, diallyl (meth) acrylate, etc. Monomers. At least one selected from these groups can be used. Its usage is
It is 0.1 to 5.0% by weight based on the total amount of the monomers. Preferably, it is 0.1 to 3.0% by weight. The amount used
When the amount is less than 0.1% by weight, the plasticizer resistance decreases, and when the amount is more than 5.0% by weight, the film forming property and the adhesiveness decrease.

The alkyl (meth) acrylate monomer used in the present invention includes methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl. (Meth) acrylate, isobutyl (meth) acrylate, tertbutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) Acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, benzyl (meth) acrylate, lauryl (meth) Acrylate, cyclohexyl (meth) acrylate, tetradecyl (meth) acrylate, stearyl (meth) acrylate, 2-methoxyethyl acrylate, ethyl carbitol acrylate. At least one selected from these groups
Although more than one kind can be used, in particular, those having 1 to 12 carbon atoms
It is preferable to use a monomer selected from (meth) acrylic acid alkyl esters having an alkyl chain.

The amount of these (meth) acrylic acid alkyl ester monomers used is 98.4 to the total amount of the monomers.
It is preferably 60.0% by weight. If the amount is outside this range, the initial adhesive strength will decrease.

As other copolymerizable monomers used in the present invention, non-functional monomers and functional group-containing monomers can be used. Non-functional monomers include styrene, α-methylstyrene, chlorostyrene, 4-hydroxystyrene, vinyltoluene, vinyl acetate, vinyl propionate, vinyl versate, and the like.
At least one or more monomers selected from these groups can be used. The amount used is from 0 to 10.0% by weight.

Further, as the monomer having a functional group, a monomer having a functional group such as a carboxyl group, a hydroxyl group, an amide group and a carbonyl group can be used. As the functional group-containing monomer, as a carboxyl group-containing monomer, (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, and maleic acid,
2-hydroxyethyl (meth) acrylate as a hydroxyl-containing monomer, such as a half ester of itaconic acid with a straight or branched chain alcohol having 1 to 12 carbon atoms,
Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, caprolactone-modified (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth)
As amide group-containing monomers such as acrylate, (meth) acrylamide, N-methyl (meth) acrylamide, N
-Acrolein, diacetone acrylamide, formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, (meth) acryloxyalkyl propane as carbonyl group-containing monomers such as -ethyl (meth) acrylamide and N, N-dimethyl (meth) acrylamide. Nal, diacetone (meth) acrylate, acetonyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate and the like. At least one or more monomers selected from these groups can be used. Preferably, (meth) acrylic acid and 2-hydroxyethyl (meth) acrylate are used. By using the functional group-containing monomer, the stability at the time of emulsion polymerization is improved, and the plasticizer resistance of the copolymer is also improved. The amount used is 0.
5 to 10.0% by weight.

The copolymer emulsion of the present invention has a glass transition temperature (hereinafter, referred to as Tg) of the copolymer of -20 to-.
It needs to be 60 ° C. Preferably, -30 to 30
-60 ° C. When the Tg of the copolymer is higher than −20 ° C., the adhesion to the base material decreases. The Tg of the copolymer is-
When the temperature is lower than 60 ° C., the initial adhesive strength decreases. In addition,
The Tg of the copolymer is based on the standard of Japan Emulsion Manufacturers Association, “Synthetic Resin Emulsion Film and Hardness Indication Method (107-19)
96)), from the calculation formula using the Tg value of each homopolymer.

The copolymer emulsion of the present invention comprises (meth) acrylonitrile, a monomer having at least two polymerizable vinyl groups per molecule, a (meth) acrylic acid alkyl ester monomer, and other copolymers. A monomer mixture consisting of possible monomers is obtained by preparing two types of copolymer emulsions having different particle diameters by an emulsion polymerization reaction in an aqueous medium in the presence of an emulsifier, and blending them. be able to. It can also be obtained by preparing a copolymer emulsion so as to have two peaks of the particle diameter during the emulsion polymerization reaction.

The emulsifier used in the present invention is not particularly limited, but anionic emulsifier, nonionic emulsifier and reactive emulsifier can be used. As anionic emulsifiers, specifically, potassium oleate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate And polyoxyethylene alkyl ether phosphates and polyoxyethylene alkyl allyl ether phosphates. Specific examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethyleneoxypropylene block copolymer, polyethylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester. As the reactive emulsifier, specifically, polyethylene glycol mono (meth) acrylate, polyoxyethylene alkylphenol ether (meth) acrylate having various molecular weights (different EO addition moles),
Examples thereof include ammonium 2- (meth) acryloyloxyethylene sulfonate, monomaleic acid esters of polyoxyethylene glycol and derivatives thereof, and (meth) acryloyl polyoxyalkylene alkyl ether phosphate esters. At least one selected from these groups can be used.

The amount of emulsifier used is usually 10
It may be used in an amount of about 0.2 to 10.0 parts by weight, preferably 0.5 to 6.0 parts by weight, based on 0 parts by weight.
When the amount of the emulsifier used is within this range, the particle size of the copolymer emulsion of the present invention can be obtained without forming a coagulated product, and the miscibility between the copolymer emulsions can be improved.

When emulsion-polymerizing the copolymer emulsion of the present invention, a chain transfer agent can be used to adjust the degree of polymerization, if necessary. Examples of the chain transfer agent used include n-dodecyl mercaptan, 2-mercaptoethanol, n-butyl mercaptan, trichloromercaptan, and isopropyl alcohol. At least one selected from these groups can be used.

As the polymerization initiator used in emulsion polymerization of the copolymer emulsion of the present invention, polymerization initiators used in ordinary emulsion polymerization can be used, and ammonium persulfate, potassium persulfate, persulfate and the like can be used. Examples include sodium, hydrogen peroxide, peroxides of peroxyesters, and azobis-based polymerization initiators. Water-soluble polymerization initiators selected from these groups are preferred. Also, ferrous chloride, ferrous sulfate, sodium bisulfite, L-ascorbic acid, L-
A reducing agent such as sodium ascorbate and a peroxide can be used in combination. The amount of the polymerization initiator used is
Usually 0.02-3.
0 parts by weight. Preferably it is 0.05 to 1.0 part by weight.

The adhesive composition for flooring of the present invention may contain, if necessary, known additives such as fillers, pigments, viscosity modifiers, defoamers, preservatives, dispersants, antioxidants, and ultraviolet absorbers. An agent, an ultraviolet stabilizer, an antifreezing agent, a flame retardant, a flame retardant and the like can be blended within a range not to impair the effects of the present invention.

[0022]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition,
Parts in Examples show parts by weight, and% shows% by weight.

Production Example 1 (Copolymer Emulsion A-1) 43.5 parts of ion-exchanged water and 4 parts of sodium polyoxyethylene nonylphenyl ether sulfate (trade name Levenol WZ manufactured by Kao Corporation) were previously placed in a container. -Ethylhexyl acrylate 79.5 parts, methyl methacrylate 5
Parts, acrylonitrile 9.5 parts, methacrylic acid 3.5
, 2.0 parts of 2-hydroxyethyl acrylate and 0.5 parts of divinylbenzene are weighed and stirred to prepare a monomer emulsion mixture. In a reactor equipped with a stirrer, a reflux condenser, a thermometer, a dropping device, and a nitrogen gas inlet tube, 15.3 parts of ion-exchanged water and sodium polyoxyethylene nonylphenyl ether sulfate (trade name: Revenol WZ, manufactured by Kao Corporation) 0.8 parts, previously prepared monomer emulsion mixture
After charging 65 parts and replacing with nitrogen gas, the internal temperature is raised to 60 ° C. while stirring, and 2.5 parts of a 10% aqueous solution of sodium persulfate is added. Raise the internal temperature to 80 ° C,
Emulsion polymerize for 20 minutes. At the same temperature, the polymerization reaction is carried out for 4 hours while dropping the remaining monomer emulsion mixture. Internal temperature 80
After a further 2 hours, the reaction is carried out while maintaining the temperature. After post-reaction,
Cool to room temperature. Obtained copolymer emulsion A-
1 has a viscosity of 1060 mPa · s / 25 ° C. and a solid content of 60.
6%, pH 3.8, Tg-49.6 ° C, average particle size 16
It was 5 nm.

Production Examples 2 and 3 (Copolymer emulsion A
-2 and A-3) Copolymer emulsions A-2 and A-3 were produced in the same manner as in Production Example 1, except that the monomer components were changed. The obtained copolymer emulsion A-2 had a viscosity of 860 mPa · s.
/ 25 ° C, solid content 60.3%, pH 3.9, Tg-4
2.3 ° C., the average particle diameter is 314 nm, and the obtained copolymer emulsion A-3 has a viscosity of 1250 mPa · s /
25 ° C, solid content 60.5%, pH 4.0, Tg-49.
At 5 ° C., the average particle diameter was 113 nm.

Production Example 4 (Copolymer Emulsion B-1) 43.5 parts of ion-exchanged water and 4 parts of sodium polyoxyethylene nonylphenyl ether sulfate (trade name Levenol WZ manufactured by Kao Corporation) were previously placed in a container. -81.5 parts of ethylhexyl acrylate, 5 parts of styrene, 7 parts of acrylonitrile, 3.5 parts of acrylic acid, 2 parts of 2-hydroxyethyl acrylate, and 1 part of divinylbenzene were weighed and stirred to prepare a monomer emulsion mixture. I do. A reactor equipped with a stirrer, a reflux condenser, a thermometer, a dropping device, and a nitrogen gas inlet tube was charged with 15.3 parts of ion-exchanged water, and purged with nitrogen gas. Then, the internal temperature was increased to 80 ° C. while stirring. After heating, 2.5 parts of a 10% aqueous solution of sodium persulfate is added, and the polymerization reaction is immediately carried out for 4 hours while dropping the previously prepared monomer emulsion mixture. The reaction is carried out for another 2 hours while maintaining the internal temperature at 80 ° C. After the post-reaction, cool to room temperature. The resulting copolymer emulsion B-1 had a viscosity of 46
0 mPa · s / 25 ° C., solid content 60.5%, pH4.
0, Tg-53.2 ° C., average particle size 937 nm.

Production Examples 5 and 6 (Copolymer emulsion B
-2 and B-3) Copolymer emulsions B-2 and B-3 were produced in the same manner as in Production Example 4, except that the monomer components were changed. The resulting copolymer emulsion B-2 had a viscosity of 390 mPa · s
/ 25 ° C, solid content 60.2%, pH 3.8, Tg-3
0.5 ° C., the average particle diameter is 1430 nm, and the obtained copolymer emulsion B-3 has a viscosity of 430 mPa · s /
25 ° C, solid content 60.4%, pH 3.9, Tg-53.
At 2 ° C., the average particle size was 1017 nm.

Production Example 7 (Copolymer emulsion C-1) 43.5 parts of ion-exchanged water and 4 parts of sodium polyoxyethylene nonylphenyl ether sulfate (trade name Levenol WZ manufactured by Kao Corporation) were previously placed in a container. -Ethylhexyl acrylate 57.5 parts, butyl acrylate 2
4 parts, 9.5 parts of methyl methacrylate, 3 parts of acrylonitrile, 3.5 parts of acrylic acid, 2 parts of 2-hydroxyethyl acrylate, and 0.5 part of trimethylolpropane trimethacrylate were weighed and stirred to obtain a monomer emulsion mixture. Adjust the liquid. Ion-exchanged water was added to a reactor equipped with a stirrer, reflux condenser, thermometer, dropping device, and nitrogen gas inlet tube.
After charging 0.8 parts and purging with nitrogen gas, the internal temperature was heated to 80 ° C. while stirring, 7.5 parts of a 10% aqueous solution of sodium persulfate was added, and immediately the previously prepared simple substance was added. The polymerization reaction is carried out for 4 hours while dropping the monomer emulsion mixture. The reaction is carried out for another 2 hours while maintaining the internal temperature at 80 ° C. After the post-reaction, cool to room temperature. The obtained copolymer emulsion C-1 had a viscosity of 410 mPa · s / 25 ° C. and a solid content of 6
0.6%, pH 4.0, Tg-47.0 ° C., a particle size distribution of 500 to 1200 nm, and an average particle size of 73
It was a copolymer emulsion having a wide particle distribution of 8 nm.

[0028]

[Table 1]

The monomers shown in Table 1 are represented by the following abbreviations. Monomer: 2-EHA: 2-ethylhexyl acrylate (Tg: -70 ° C) BA: butyl acrylate (Tg: -52 ° C) EA: ethyl acrylate (Tg: -22 ° C) MMA: methyl methacrylate (Tg: 105 ° C) ) ST: Styrene (Tg: 100 ° C) AN: Acrylonitrile (Tg: 105 ° C) AAc: Acrylic acid (Tg: 106 ° C) mAAc: Methacrylic acid (Tg: 185 ° C) 2-HEA: 2-hydroxyethyl acrylate (Tg) : -15 ° C) DBV: divinylbenzene DAF: diallyl phthalate TMPTMA: trimethylolpropane trimethacrylate

Example 1 The copolymer emulsion A-1 obtained in Production Example 1 and the copolymer emulsion B-1 obtained in Production Example 4 were blended at a solid content ratio of 20 parts: 80 parts by weight. Then, the pH is adjusted to about 8 with 25% ammonia water. Further, an emulsion-type alkali thickening type thickener (manufactured by Seiden Chemical Co., Ltd., trade name: Cyvinol AZ-1) is gradually added, and the viscosity is adjusted to 5000 to 7000 mPa · s / 25 ° C. to prepare an adhesive. Then, the resulting flooring adhesive was tested by the test method described below, and as a result, both the plasticizer resistance of the coating film on the glass plate and the peelability between the zinc steel plate and the tile carpet were good. . The initial adhesive strength between the zinc steel sheet and the loose lay tile was as high as 69.1 N / 50 cm ² , and the strength retention strength was 72.1%, and the influence of the plasticizer was small. Table 2 shows the results.

Examples 2 to 5 Examples 2 to 5 were blended at the ratios shown in Table 2 and adjusted in the same manner as in Example 1 to prepare an adhesive, and tested in the same manner as in Example 1. As a result, the plasticizer resistance, peelability, initial adhesive strength and strength retention were all good. Table 2 shows the results.

Comparative Example 1 In Comparative Example 1, an adhesive was prepared by using the copolymer emulsion A-1 having a small particle diameter peak obtained in Production Example 1 and adjusting it in the same manner as in Example 1. Then, as a result of a test conducted in the same manner as in Example 1, the initial adhesive strength was 74.3 N / 50c.
Although it was as high as m ² , the plasticizer resistance, peelability and strength retention were low. Table 2 shows the results.

Comparative Example 2 In Comparative Example 2, an adhesive was prepared by using the copolymer emulsion B-2 having a large particle diameter peak obtained in Production Example 5 and adjusting it in the same manner as in Example 1. However, as a result of a test conducted in the same manner as in Example 1, the plasticizer resistance, peelability, initial adhesive strength, and strength retention were low. Table 2 shows the results.

Comparative Example 3 In Comparative Example 3, the average particle diameter obtained in Production Example 7 was 738 n.
Using a copolymer emulsion C-1 having a wide particle distribution of m, an adhesive was prepared in the same manner as in Example 1 and tested in the same manner as in Example 1. As a result, the plasticizer resistance and peeling were obtained. The properties, initial adhesive strength and strength retention were low. Table 2 shows the results
Shown in

[0035]

[Table 2]

Test method Particle size The particle size is determined by NICOMP Model 370 (Particle Sizi
ng Systems Inc.). 2. Plasticizer Resistance The obtained flooring adhesive was applied onto a glass plate (width 50 mm, length 150 mm, thickness 2 mm) at an application amount of 100 g / m 2.
So that ² · wet uniformly coated, 23 ℃, 65%
After curing for 3 days in an RH atmosphere, a sample was obtained. This sample was immersed in DOP at room temperature and left for 7 days. After standing, the dissolution state of the adhesive film was observed. ◎: Slight swelling of the film ○: Slightly dissolving the surface of the film △: Partially dissolved and the shape of the film is disturbed ×: Completely dissolved Peelability The obtained adhesive for flooring was applied with a width of 100 mm and a length of 250 m.
m, a coating amount of 70 g / m ² on a zinc steel sheet having a thickness of 1 mm.
・ Apply so as to be wet and leave at room temperature for 60 minutes. After standing, width 100 mm, length 250 mm, thickness 6.
5mm tile carpet (product name GA manufactured by Tori Co., Ltd.)
-100, made of flexible PVC)
After pressure bonding for 0 second, it was left in an atmosphere of 50 ° C. for 14 days.
After allowing to cool to room temperature, the tile carpet is peeled off by hand, and the degree of transfer of the adhesive to the back of the tile carpet is observed. : No adhesive transfer ○: Approximately 10% of the adhesive is transferred △: Approximately half of the adhesive is transferred ×: Adhesive is transferred over the entire surface Initial adhesive strength The obtained adhesive for flooring is applied to a width of 100 mm and a length of 250 m.
m, a coating amount of 50 g / m ² on a zinc steel sheet having a thickness of 1 mm.
・ Apply so as to be wet and leave at room temperature for 60 minutes. After standing, width 50mm, length 100mm, thickness 2mm
Of "Push-Pull Scale" (manufactured by Imada Manufacturing Co., Ltd.) with 5 kg load applied to the loose-lay tiles (LL Free 600, manufactured by Tori Co., Ltd.)
The film was pulled in the horizontal direction by using, and the initial adhesive strength was measured.
The measurement was performed in an atmosphere at 23 ° C. and 65% RH. 5. Strength retention This measurement is based on the consideration of the plasticizer resistance in terms of adhesive strength. It is considered that the higher the strength retention, the higher the plasticizer resistance of the adhesive film. The measurement method was such that a sample obtained with an initial adhesive strength was left in an atmosphere at 50 ° C. for 14 days. After standing, it was cooled to 23 ° C. and 65% RH for 24 hours, and the adhesive strength was measured at that temperature in the same manner as the initial adhesive strength. The strength retention was determined by the following equation. Strength retention (%) = measured adhesive strength / initial adhesive strength × 100

[0037]

The adhesive for flooring of the present invention has a specific two kinds of particle size distributions and Tg, and consists of a copolymer emulsion having a limited composition, which cannot be obtained with a normal copolymer. It exhibits excellent plasticizer resistance and releasability, and exhibits excellent adhesive performance for a PVC flooring material containing a large amount of plasticizer without causing displacement, peeling, or scorching over time.

Claims (2)

[Claims] 1. A copolymer comprising acrylic crosslinked particles has a glass transition temperature of -20 to -60 ° C., a particle diameter peak (A) region of 50 to 500 nm, and a particle diameter peak of 900. An adhesive composition for flooring having two particle size peaks in the (B) region of ２０００2000 nm. 2. A copolymer comprising acrylic cross-linked particles containing (meth) acrylic acid alkyl ester monomer as a main component, (meth) acrylonitrile in an amount of 1.0 to 15.0% by weight, and Emulsion polymerization of a monomer mixture comprising 0.1 to 5.0% by weight of a monomer having at least two polymerizable vinyl groups (total amount of monomers is 100% by weight) in an aqueous medium. The adhesive composition for flooring according to claim 1, which is a copolymer emulsion comprising: