CA2010556C - Method of installing tile-like floor material - Google Patents

Abstract

The present invention provides a pressure sensitive adhesive for tile-like floor materials characterized in that the adhesive comprises a polymer A
0.05 to 4 µ in particle diameter and a polylner B 5 to 150µ in particle diameter and in combination therewith, the polymer B being lower than the polymer A in glass transition point, and a method of installing the tile-like floor material with use of the adhesive.

Description

20105~6 Method of installing tile-like floor ~naterial The present invention relates to a pressure sensitive adhesive useful for installin~ a tile -like floor Material such as tile carpet, and to a rnethod of installing the tile -like floor rnaterial witll use of the adbesiYe.
When tbe tile -like floor ~aterial to be installed is rnerely placed on the sub-floorin~ without applyin~ any adllesive, there arises tlle problern that tlle floor rnaterial becoroes dislod~ed by walking durin~ use.
H owever, use of an adhesive of hi~h stren~th is not desirable since t!~e adhesive is likely to cause darna~e to the backin~ of the floor rnaterial or to the sub- floorin~
when the floor rnaterial fixed is to be installed in a different place or when the carpet is removed for ~aintenance durin~ use.
An object of the present invention is to provide a pressure sensitive adhesive for tile -like floor Materials which has suitable adhesion and which perrnits tbe floor rnaterial as installed to be readily rernoved, and a Metbod of installin~ the tile-like floor rnaterial usin~ the adhesive.
Tbe above and other objects of the invention will becoMe apparent fro~ the followin~ description.
The present invention provides a pressure sensitive adbesive for tile -like floor rnaterials ~,`

2010~6 characterized in that the adhesive comprises a polymer A
0.05 to 4 ~ in particle diarneter and a polyrner B 5 to 150~ in particle diarneter and in coMbinatioll therewitll, the polymer B being lower than the polyrner A in glass transition point, and a rnethod of installillg the tile -like floor material ~ith use of the adhesive.
Accordin~ to the invelltioll, the polyrner A
cornprises a single synthetic resin, natural rubber, synthetic rubber or like adhesive composition or a mixture of such adhesive compositions. Useful synthetic resin compositiolls are tbose of a vinyl hornopolymer or copolyrner, whicll is preferably a polyrner consisting prirnarily of an acrylic acid ester or rnethacrylic acid ester. While the properties required of the polymer are adjustable according to the kind and amount of nonomer containin~ a functional group and to be used, the properties are adjustable also by controlling the glass transition point of the polyrner A insofar as the adhesion of the polyrRer is not iDpaired. The ~ean particle diarneter of the polymer A
~ 20 is preferably 0.05 to 4 ~ , more preferably 0.05 to 1 ~ , to ensure penetration into the sub-flooring and intirnate contact with the floor rnaterial.
According to the invention, the polyrner B is in the form of rnicrospberes having a rnean particle diarneter of 5 to 150~ , preferably 20 to 60~. For exalnple, the polyrner B is in the form of adhesive polymer microspheres prepared from (a) 70 to 99.9 wt. %

2010~56 of an alkyl (Meth)acrylate havin~ an alkyl ~roup with 4 to 12 carbon atoMs, (b) 0.1 to 10 wt. % of an unsaturated carboxylic acid and (c) O to 29.9 wt. % of a vinyl coMpound other than the two cotnponents (a) and (b~, by subjectin~ these coMponent MonoMers to aqueous suspension polyMerization. ExaMples of useful alkyl (~eth)acrylates (a) havin~ an alkyl group with 4 to 12 carbon atoMs are n- butyl (Meth)acrylate, isobutyl (meth)acrylate, tert- butyl (Meth)acrylate, n- pentyl (Meth)acrylate, n -heKyl (Meth)acrylateJ 2 -etbylhexyl (Ineth)acrylate~ isooctyl (Meth)acrylate, isononyl (Ineth)acrylate, lauryl (Ineth)acrylate and the like.
ExaMples of useful ~, ~ -unsaturated carboxylic acid (b) are acrylic acid, Methacrylic acid, Inaleic acid, fuMaric acid, itaconic acid and the like. E xalnples of useful vinyl MonoMers (c) are vinyl acetate, vinyl propionate, Methyl (Meth)acrylate, ethyl (Meth)acrylate, styrene, acrylonitrile, 2-hydroxyethyl (Meth)acrylate, N,N-dilnethyl-aMinoethyl acrylate, acrylaMide, diacetone acrylaMide, N -~ 20 MethylolacrylaMide, ~Iycidyl (laeth)acrylate, aziridinylethyl (Meth)acrylate and the like. The adhesive Microspheres of poly~er B can be prepared easily by the usual process of aqueous suspension polyMerization. U seful dispersants are anionic surfactants and nonionic surfactants, which ~nay be used sin~ly or in adMixture. T he Inicrospheres can be prepared easily when a protective colloid is used. The particle dia~eter is adjustable by suitably deterMinin~ the 2010S~6 kinds and arnounts of surfactant and protective colloid to be used and also by employin~ a particular Method for the poly~nerization reaction. The desired particle diarneter C811 be obtained, for exarnple, by usin~ an in~enious Method of addin~ the rnollo1ner or e~ulsion dropwise wben seed polyrnerizati 011 or Inu lti -sta~e polymerization is resorted to. The modulus of elasticity of the adhesive polyrner rnicrosplleres can be adjusted easily by usin~
divinylbellzene, trimetllylolpropalle triacrylate or the like.
I t is also possible to filter off tbe adhesive polymer microspheres only from the aqueous suspension, dryill~ the particles at a low ternperature and dissolvin~ the particles in an or~anic solvent for use. While the polyMer B is used in an amount of 10 to 100 parts by wei~ht per 10Q parts by wei~ht of the nonvolatile content of the polymer A, it is desirable to use 10 to 50 parts by weig11t of the polymer B to afford adhesion and re1easabi1ity. When applied and dried, the fine polymer - particles becorne arran~ed on the surface of tbe floorin~
to be covered with the floor rnaterial, playin~ an irnportant role in ~ivin~ adjusted adhesion.
Accordin~ to the present invention, it is desired that the polyrner A be at least -50 C in ~lass transition point ( Tg) and that the polyrner B be lower than - 50-C in Tg. Thus, the polyrner B is lower than the polyrner A in Tg at all tirnes. Accrodin~ to the invention, it is essential that the polyrner B be lower 2010~5B

in T ~ and hi~her in modulus of elasticity.
Accordin~ to the invention, the coMbination of the polymer A and tbe polytner B exhibits the contemplated function. S tated ~nore specifically, the adhesive, when applied, exhibits the contelnplated functio presurnably throu~b the followin~ process. Tl-e cornponent polymer A, which is as small as 0.05 to 4 ~ in particle size, smootllly spreads over and penetrates into the sub- floorin~, i.e., concrete. Accordin~ly, when the adhesive is applied to the surface of concrete, the polymer A immediately spreads to wet the surface and produce an adherin~ effect, further permittill~ substances chiefly includin~ water to penetrate into the interior of concrete. This effect contributes to the dryability and intimate contact with the concrete, with the result that when the floor Inaterial is affixed to the concrete, the adhesive exhibits hi~her stren~th on the concrete surface and lower stren~th on the floor material. Accordin~ly, when the adhered floor Material is to be removed, the adhesive is less likely to be transferred onto the material. This assists in achieving the object of the invention.
However, the requireMent of releasability can not be fully fulfilled only with this feature; the above effect needs to be enhanced by the polyrner B. S ince the polylner B is lar~er in particle size, this polylner is unable to spread and penetrate s~noothly and therefore 20~0~56 eventually beco~es arran~ed in intirnate contact with the back surface of the floor Material. Because of this pheno~nelloll, the adhesive, wben applied, has on the surface lar~e and elastic particles which, althougll undergoin~
elastic deforrhation whell subjected to pressure, re~ain free of deforlhation in contact with the back surface of the floor Material and the surface of the sub-flooring over a dirninislled area when not subjected to pressure~ as conte~nplated by tbe present invention. The cornbination of the poly~ner A and the poly~er B accordin~ to the invention therefore affords a pressure sensitive~ adhesive which exhibits adherin~ ability along witll releasability and whicb is hi~hly suitable for use with floor ~Daterials.
S ince the present pressure sensitive adhesive cornprises the poly~ner A and t~e polyrner B wh ich are different in elasticity, the p~y~ngr A which is soft is in intifnate contact with the entire surface of the floor ~aterial to prevent the separation of the ~aterial during use, while the polyrner B which is elastic relnains free ~ 20 of defor~ation in contact with the back surface of the floor rnaterial and with the sub- floorin~ (~round floorin~) over a sMall area when not subjected to any pressure althou~h undergoin~ elastic deforrhation when pressed on.
Thus, the co~nbination of two polyrners ~ives adhesion and releasability, renderin~ tbe present pressure sensitive adhesive very suited for use with floor materials.
To i~npart enhanced tackiness to the present adhesive, an aqueous dispersion of natural resin and/or pertroleu~ resin ~ay be added to the adhesive as a poly~er C when so desired. Exa~0ples of useful natural resins and petroleuln resins are aliphatic hydrocarbon resins, arolnatic petroleuln resins, cyclopentadielle resins, polyterpene resins, modified terpenes, rosinl rosin esters, hydro~ellated rosin esters, phenolic resins, styrene resins, xylene resins and the like. A queous dispersions of natural resins and petroleu~ resins are necessary for givin~ adjusted adhesion and afford such adhesion, dryability, and anchora~e and penetration into the sub-floorin~ that are in no ~ay available with adhesives colnposed only of synthetic resins or rubbers. These resins can be used in an alnount of up to about 50 parts by wei~ht per 100 parts by wei~llt of the nonvolatile content of the poly~ner A. Besides these resins, solvents such as alcohols, toluene and the like ~ay be added to the adhesive.
The present invention further provides a ~ethod ~ 20 of installing a tile-like floor Inaterial characterized by providin~ the pressure sensitive adhesive described above between the tile-like floor Inaterial and sub-flooring.
The present invention will be described below with reference to the drawin~. Fig. 1 is a sectional view showin~ how the invention is practiced. Indicated at 1 is the pile of tile carpet, and at 2 a resin backin~. Tbe pressure sensitive adhesive 3 of the 2010~6 invention is provided between the resin backin~ 2 and sub- flooring G. The adhesive 3 rnay be applied to the sub- floorin~ G when the tile carpet is to be laid, or provided as applied to the backin~ of the tile.
Accordin~ to the invention, the pressure sensitive adhesive comprises a polyrner 4 and a poly~ner 5 in - cornbillation therewith. The polyrner 4 is the polyrDer A.
Indicated at 4 is the polyrner A penetratill~ into the entire surface of the sub- floorin~ and contributin~ to the adhesioll of the backing 2. The polyrner 5 is the polylner B. The polyrner 4 is hi~her than polymer 5 n When the tile-like floor rnaterial is adhered to the sub-floorin~ with use of the adhesive of the structure described, the polyMer A which are in the forrn of srDall soft rnicrospheres is in contact with the sub-floorin~ G and the backin~ 2 over a lar~e area. O n the other hand, the polyrner B which is usually spherical and elastic deforrns to a flat shape when subjected to a load, contactin~ the sub-floorin~ over an increased area to e~hibit enhallced stren~tll. The adhesive has sucb characteristics that wllen a peelin~ force ~reater than a ~iven Ma~nitude acts on tlle floor rnaterial, the rnaterial easily peels off. T hese characteristics give ~ood results to the prevention of dislod~in~ and the adhesion- peelin~
cycle, renderin~ the adhesive very valuable for use with floor rnaterials. While the floor rnatrials for use in -2010S~6 the present invention rnay be ~nade of synthetic resins, ceranics, wood or the like, tile carpet and other flexible tile - like floor lnaterials are suitable.
(1) W hell the present pressure sensitive adhesive is used for installin~ tile carpet, good adhesiol- and releasability can be obtained, preventing the carpet froln dislod~in~ due to walkin~. The tile car~Jet can be peeled off easily for reinstallation in the evellt of error or for lnaintenance durin~ use.

(2) W hell the floor ~aterial is installed in place witll use of the present pressure sensitive adhesive and thereafter peeled off, the backing on the Inaterial rernains free of dalna~e.

(3) W hen the floor ~aterial is installed in place witll use of the present pressure sensitive adhesive and thereafter peeled off, no adhesive sticks to the backin~ of tbe floor ~ater;al.

(4) T he floor lnaterial can be installed with ilnproved efficiency since there is no need to consider tlle open tilne of the adhesive.
Fi~. 1 is a sectional view showing the Inethod of the invention as practiced.
The invention will be described in detail with reference to the exaMples and comparative exalnples.
Exalnple I nto a three-necked flask equipped with a ther~nolneter, reflux condenser and speed- variable stirrer 201~5~6 .

were placed 85 parts (hy wei~ht, the sarne as hereillafter) of butyl acrylate, 12 parts of vinyl acetate, 3 parts of acrylic acid, 2.0 parts of anionic surfactant, 0.5 part of nonionic surfactant and 100 parts of iOIl -exehanged water, ~hich were then heated with stirrin~ in a nitro~en strea~n. When the te~nperature of the reaction systern reached 50~, the systern was initiated into polyrnerization with addition of 0.5 part of arnrDoniuln persulfate servin~ as a polyrnerizatioll initiator. The polyrnerization reaction was conducted at 80 C for about 3 hours. O n colnpletion of polyrnerizatioll, the reaction rnixture was heated to about 85 C and further reacted for 1 hour to obtain a copolyMer ernulsion cornposition. T o the e~ulsion cornposition was added 25% of aqueous solutioll of arnlnonia dropwise witll stirrin~ to prepare an acrylic copolyrner eMulsion havin~ a viscosity of 8,000 cp (30 C) and -a nonvolatile content of 51.5%. The ernulsion was -43-C in ~lass transition point as deterMined by a differential scannin~ calorilneter, D S C -200 (product of ~ 20 S eiko D enshi Ko~yo Co., L td. ) and 0.3~ in Mean particle diaMeter as rneasured by a sublnicron particle analyzer, Model N 4 (product of Coulter Electronics Inc.). The ernulsion copolylner obtained will be referred to as the ~polylner A".
N ext, 100 parts of water and 3 parts of 20%
solution of an incornpletely saponified product of polyvinyl alcohol were thorou~hly stirred in a container for ~1)10~ ~

preparin~ a polylner B S ubsequently, 45 parts of 2-ethylllexyl acrylate, 5 parts of butyl acrylate, 1.0 part of acrylic acid and 0.5 part of benzoyl pero~ide were stirred in another conta;ner to obtain a solution. The solution of ~nonolner Inixture was added to the aqueous solutioll prepared preriously, followed hy stirrin~. The nixture started polylnerization at a stirrin~ speed of 100 r.p.m. at a telnperature of 70 to 75 C and evolYed heat Markedly at 85 to 95-C. The IniKture was thell cooled to $1 to æ2 C for a further reaction for 2 hours, whereby an aqueous suspension of uniforM particle size was produced in the reactor. The suspension was then subjected to the subsequent polylnerization process. 2 -Ethylhexyl acrylate (50 parts), 0.5 part of anionic surfactant, 1.5 parts of acrylic acid, 0.5 part of benzoyl peroxide and 50 parts of water were fully Inixed to~ether with stirrin~ in another container. The whole aMount of the Inixture was added dropwise to the suspension over a period of 30 ~inutes, and the ~ixture ~ 20 was reacted at 80 to 83-C for 4 hours. The reaction nixture was thereafter cooled and taken out to obtain an adhesiYe in the forM of an aqueous suspension, wbicll was 1,500 cp in viscosity (30 C), 40% in nonvolatile content and -~8-C in T~. The suspension was 50~ in ~ean particle dia~eter as ~easured in a state cooled with liquid nitro~en by a scannin~ electron Inicroscope J S M
(product of J O E L, L td. ) havin~ Cryo U nit attacbed 2010~5~

to its body.
Next, the compollent polylner A, tbe component polyMer B and an aqueous dispersion (50% nonvolatile content) of ~Iycerin ester of hydro~enated rosin servin~
as a coMponent C were mixed to~ether in the A : B:C
ratio of 100:~0:20 (by weight). W ith addition of defoamill~ agent, antioxidant and preservative, thc Mixture was stirred for 60 rninutes to obtain a pressure sensitive adhesive for tile -like floor rnaterials. Tbe adhesive was 46.7% in nonvolatile content and 3,000 cps in viscosity (25 ~).
The adhesive ~as applied to a concrete surface in an amount of 100~/m2 witb a trowel, tile carpet havin~ polyvinyl cbloride backin~ layer was affixed to the concrete under the condition stated below, peeled off about 1.5 ~nonths later and checked for adhesion, releasability and transfer of the adhesive to the back surface of the tile carpet.
ExaMple 2 ~ 20 Tile carpet was installed in the sarne rnallner as in ExaMple 1 with a pressure sensitive adhesive prepared by the saMe procedure as in ExaMple 1 with the exception of not usin~ the component C.
Exa~nple Tile carpet was installed in the sarne Manner as in ExaMple 1 with use of a pressure sensitive adbesive prepared by the saMe procedure as in ExaMple 1 except that the~ colnponent A used was an acrylic adbesive, S aivinol A t- 351 - 1 (product of S aiden Chemical Industry Co., L td. , 8,500 cp in viscosity, 50% in nonvolatile content, 0.8~ in particle dialneter and -40-~
in ~lass transition telnperature~.
E xalnple 4 Tile carpet was installed in the sarne Inanner as in Exarnple 1 with use of a pressure sensitive adhesive prepared by the salne procedure as in Exarnple 3 with tbe exceptioll of not usin~ the colnponellt C.
Comparative E xa~nple T he carpet was installed in the sarne Inanner as in E xa~nple 1 with use of a pressure sensitive adllesive prepared by the salne procedure as in Exalnple 1 with the exceptioll of not usin~ tlle coMponent B.
Colnparative E xaMple 2 The carpet was installed with use of an adllesive prepared by addin~ 20 parts of aqueous dispersion of ~lycerin ester of hydro~enated rosin as a colnponent C
to 100 parts of S B R latex (69 % in nonvolatile content~
and furtller addin~ a plasticizer, surfactant, defoamin~
a~ent and antioxidant to the Inixture. T able 1 shows the results.

~t~ ~kRk 201055~

Table Exarnple Corn. Ex.
1 2 3 ~ 1 2 Initial tack a A A A A A A
b A A A A A A
c A A A A A A
d A A A A A B
e A A A A B B
Adhesion after peelin~
a A A A A A B
b A A A A A B
c A A A A A B
d A A A A A B
e A A A A A B
T ransfer to the backin~
a A A A A C B
b A A - A A C B
c A A A A B B
d A A A A B A
e A A A A B A
~ Releasability A A A A B B

N ote) 1. Initial tack A: the adhesive has sufficient initial tack B: the adhesive has no initial tack 2. Adhesive after peelin~
A: the adhesive has ~ood adhesion after peelin~

20105~

B: tbe adhesive bas insufficient adhesion after peelin~
3. T ransfer to tbe backin~
A: no adbesive is transferred B: tbe adhesive is sli~btly transferred C: tbe adbesive is markedly transferred 4. Releasability A: tbe adbesive bas excellent releasability B: the adbesive bas insufficient releasability The adl)esive was applied with an open tiMe of O minutes for ~an, witll an open time of 10 minutes for ~bn, 60 Ininutes for ~cn, 300 minutes for ~d" and 600 ....
rnlnutes for e .
In E xamples 1 to 4, each pressure sensitive adbesive had sufficient initial tack and exhibited ~ood adhesion a~ain after tbe tile carpet was removed irrespective of the open time. Further none of the adbesive was transferred to tbe carpet backin~. Tbis indicates excellent releasability.
In Cornparative Exarnple 1, tbe pressure sensitive adbesive had no initial tack, and transfer of the adhesive occured in case e. In Comparative Exarnple 2 , the pressure sensitive adhesive in cases d and e had no initial tack nor any adbesion after peelin~, was transferred to the backin~ and was therefore unsuited as a pressure sensitive adbesive with releasability.

Claims (4)

1. A method of installing a tile-like floor material comprising providing a pressure sensitive adhesive between the tile-like floor material and sub-flooring, the adhesive comprising a polymer A having a mean particle diameter of from 0.05 to 4 µ and a polymer B having a mean particle diameter of from 5 to 150 µ and in combination therewith, the polymer B being obtained by aqueous suspension polymerization in the presence of a partially saponified polyvinyl alcohol and being lower than the polymer A in glass transition point, wherein the polymer A is one selected from the group consisting of vinyl homopolymer, vinyl copolymer, natural rubber and synthetic rubber, and wherein the polymer B is in the form of adhesive polymer microspheres prepared from (a) 70 to 99.9 wt. % of an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms, (b) 0.1 to 10 wt. % of an .alpha.,.beta.-unsaturated carboxylic acid and (c) up to 29.9 wt. % of a vinyl compound other than the two components (a) and (b), by subjecting these component monomers to aqueous suspension polymerization.

2. A method as defined in claim 1, wherein a natural resin or petroleum resin is further added to the adhesive, in an amount of up to about 50 parts by weight per 100 parts by weight of the nonvolatile content of the polymer A.

3. A pressure sensitive adhesive for a tile-like floor material, comprising a polymer A having a mean particle diameter of from 0.05 to 4 µ and a polymer B having a mean particle diameter of from 5 to 150 µ and in combination therewith, the polymer B being obtained by aqueous suspension polymerization in the presence of a partially saponified polyvinyl alcohol and being lower than the polymer A in glass transition point, wherein the polymer A is one selected from the group consisting of vinyl homopolymer, vinyl copolymer, natural rubber and synthetic rubber, and wherein the polymer B is in the form of adhesive polymer microspheres prepared from (a) 70 to 99.9 wt. % of an alkyl (meth)acrylate having an alkyl group with 4 to 12 carbon atoms, (b) 0.1 to 10 wt. %
of an .alpha.,.beta.-unsaturated carboxylic acid and (c) up to 29.9 wt.%
of a vinyl compound other than the two components (a) and (b), by subjecting these component monomers to aqueous suspension polymerization.

4. An adhesive as defined in claim 3, wherein a natural resin or petroleum resin is further added to the adhesive, in an amount of up to about 50 parts by weight per 100 parts by weight of the nonvolatile content of the polymer A.