CA2118017A1 - Topographical method - Google Patents

Abstract

A method for imparting topographical features to a permanent substrate employing a sheet material comprising a thermosettable pressure-sensitive adhesive composition. The edges of the sheet material are caused to flow prior to the thermosetting reaction to provide smooth transition lines between an exposed surface of the sheet material and the permanent substrate.

Description

wo 93/23487 Pcr/US93/03469 TOPOGRAPHICAL METHOD

FIELD OF THE INVENTION
This invention relates to a method for providing topographical 5 features to a substrate. `
~.

BACKGROUND OF THE INVENTION -U.S. Patent No. 5,086,088 discloses a latent, thermosettable pressure-sensitive adhesive composition comprising an acrylate pressure-10 sensitive adhesive and an epoxy resin component which provides for thethermoset cure. The adhesive composition is disclosed as being useful to fasten roof molding to a car body.
'.'.

BRIEF SUMMARY OF THE INSTANT INVENTION ~-The instant invention provides a novel method for imparting topographical or protective features to a permanent substrate, comprising the .: ~
-~ steps of:
a) providing a dissevered, hardenable sheet material having first and second major surfaces, comprising a latent, thermosettable pressure-sensitive adhesive throughout a major portion of its thickness, and exhibiting pressure-sensitive adhesive properties at the first major surface;
b) contacting and adhering the first major surface of the sheet material to the permanent substrate or a temporary substrate leaving the second major surface of the sheet material exposed;
c) substantially thermosetting and substantially hardening the sheet material in a manner permitting initial, controlled mass flow of the sheet material substantially in its thickness direction to provide a substantially smooth transition between the second surface of said sheet material and the permanent substrate or the temporary substrate to which it has been adhered; and , wo 93/23487 2 1 1 8 0 1 7 Pcr/US93/03469 ~

d) in the event the hardened sheet material is adhered to the temporary substrate, removing the hardened sheet material therefrom and thereafter fastening (e.g., adhering) the first ~major surface of the sheet material to the permanent substrate.
In a preferred method, the sheet material is adhered to the ;
perrnanent substrate in the first instance.
The method of the invention finds particular utility in the application of sheet material to primed or unprimed metal automobile parts or bodies to seal metal parts or provide emblems or insignia or design elements 10 such as trim. The resulting larninate is aesthetic since the hardened sheet ~.
material exhibits smooth, rounded edges relative to the substrate, and can be .
painted or otherwise decorated as desired to match or complement the remainder of the automobile.
Another application of the method of the invention is in the ~`~
15 fabrication of signs or the like which are then adhered to the permanent surface by means of an adhesive distinct from the sheet material exployed in making the sign or other article.
- ~ .
- DETAILED DESCRIP~ION OF THE INVENTION
20~ The sheet material employed in the method of the invention comprises a latent, thormosettable pressure-sensitive adhesive. By "pressure-sensitive~adhesive" is meant that the adhesive exhibits pressure-sensitive adhesive properties at the temperature at which the sheet material is contacted ; ~ with the permanent substrate or temporary substrate in step b) of the method.
25 Generally, the temperature involved in that step will be between ambient `"
temperature and about 400F. It is presently preferred that the adhesive exhibitpressure-sensitive adhesive properties at ambient temperature such as 22C.
- ~-;
The composition of the thermosettable pressure-sensitive adhesive contained in~~the sheet material is such that, when employed in the method of -30 the invention, its modulus decreases permitting controlled flow of the sheet material at its edges resulting in smooth transition lines between the exposed ' .

surface of the sheet material and the substrate to which it has been adhered. By -"controlled flow" is meant that there is no substantial change in the dimensionsof the sheet material in its x- and y-planes defining the first major surface.
Typically the sheet material will have been dissevered or configured in the S desired shape and dimensions by a process such as die-cutting or knife or laser slitting resulting in sharp transition lines. After the above-described controlled flow has occurred, a latent curing or crosslinking chemistry is activated to harden the sheet material and the pressure-sensitive adhesive therein.
Accompanying such hardening may be a loss of substantially all the pressure-10 sensitive adhesiveness of the sheet material. In a preferred method of theinvention, the controlled mass flow and subsequent thermosetting reaction result from heating of the sheet material.
- The sheet material used in the method of the invention comprises a latent thermosettable pressure^sensitive adhesive throughout a major portion of 15 its thickness. Preferably, the sheet material comprises the adhesive throughout - its entire thickness. -~
The thermosettable pressure-sensitive adhesive preferably comprises the photochemical reaction product of starting materials compnsing i) a prepolymeric (i.e., partially polymerized to a viscous syrup typically betweenabout 100 to 10,000 centipoises) or monomeric syrup comprising an acrylic or methacrylic acid ester; ii) an epoxy resin; iii) a photoinitiator; and iv) a heat activable hardener for the epoxy resin. Such a composition may be coated and polymerized conveniently in a variety of thicknesses including relatively thick sections .
The photopolymerizable prepolymeric or monomeric SyNp contains an acrylic or methacrylic ester and optionally a copolymerizable reinforcing comonomer. The acrylic or methacrylic ester is a monofunctional acrylic or methacrylic ester of a non-tertiary alcohol, having from about 4 to about 12 carbon atoms in the alcohol moiety. Included in this class of esters 30 are n-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, WO 93/23487 2 1 1 8 0 1 7 PCT'/US93/03469 `..' isooctyl acrylate, decyl acrylate and dodecyl acrylate. Mixtures of esters may be employed.
The copolymerizable reinforcing monomer, if employed, is~
preferably selected from the group consisting of monomers such as acrylic acid, 5 isobornyl acrylate, N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl piperidine, N,N-dimethylacrylamide, and acrylonitrile. Preferred reinforcing monomers are nitrogen-containing such as those nitrogen-containing monomers listed above. The reinforcing monomer will generally be selected such that a homopolymer prepared therefrom will have a glass transition higher than a j10 homopolymer prepared from the acrylic or methacrylic ester employed.
In the event that the prepolymeric or monomeric syrup comprises both an acrylic or methacrylic ester and a reinforcing comonomer, the acrylic or methacrylic ester will generally be present in an amount of about 50 to 95 parts by weight, and the reinforcing comonomer will be present in a 15 corresponding amount of about 50 to 5 parts by weight. One skilled in the art.~ will be able to vary the nature and amount of the reinforcing monomer to `
obtain the pressure-sensitive adhesive properties desired. -It may also be desirable to employ glycidyl methacrylate, glycidyl acrylate or another epoxy-functional monomer as a stardng material 20 together with the acrylic or methacrylic ester and reinforcing monomer, if employed. Such an epoxy-functional monomer, if employed, will preferably be 1`
present in an amount of about 0.1 to 10 parts by weight per 100 parts by weight of all monomers used.
The acrylic copolymers useful in the pressure-sensitive adhesive `
25 are very stable compositions. Because of their stability, the sheet material employed in the method of the invention may be subjected to the heat conditions required for curing the epoxy resin without degradation of the pressure-sensitive adhesive pordon of the composidon. Other types of pressure-sensitive adhesives might experience a partiat or total loss of adhesion, causing 30 detachment of the sheet material from the substrate such as a structural part to Wo 93/23487 2 1~8 0 1~ Pcr/uss3/0346s which it has been adhered prior to the conditions required? i.e., length and elevation of temperature, for thermosetting of the epoxy resin.
Further, both the photopolymerizable acrylic or methacryli~c ~;prepolymer or monomeric syrup and the photopolymerized polymer form a 5 stable mixture with the epoxy resin.
Useful epoxy resins may be selected from the group of compounds that contain an average of more than one, and preferably at least two, epoxy groups per molecule. The epoxy resin preferably is either liquid or -a semi-liquid at room temperature for handling purposes. Most preferred is a 10 mixture of a liquid and solid resin. Representative examples include phenolicepoxy resins, bisphenol epoxy resins, hydrogenated epoxy resins, aliphatic epoxy resins, and halogenated bisphenol epoxy resins. Mixtures of epoxy resins may be employed. -Preferred epoxy resins include bisphenol epoxies with the most 15 preferred epoxy resin being the diglycidyl ether of a bisphenol-A, formed by - reaction of bisphenol-A with epichlorohydrin.
The epoxy resin will generally be present in an amount of about 25 to 120 parts by weight based on 100 parts by weight of the prepolymeric or , ~ .
- monomeric syNp. i~
The photoinitiator employed to polymerize the prepolymeric or monomeric syrup may be any conventional free radical photoinitiator activatable by, for example, ultraviolet light. An example of a suitable photoinitiator is 2,2-dimethoxy-1 ,2-diphenylethane-1-one (Irgacuren'65 1 available from Ciba-Geigy Corporation). The photoinitiator will typically be employed in an amount of about 0.01 to 5 parts by weight per 100 parts of the prepolymeric or monomeric syrup.
The heat-activatable hardener is added to effect the curing of the epoxy resin under applicadon of heat. The hardener may be any type, but preferably~ an amine type hardener that is selected from the group comprising 30 dicyandiamide or polyamine salts. These are available from a variety of sources, e.g., Omicure~ available from Omicron Chemical and AjicureT#

WO 93/23487 2 1 1 8 0 1 7 PCI`/US93/03469 .

available from Ajinomoto Chemical. The heat-activatable hardener will typically be employed in an amount of about 0.1 to 20 parts by weight, and preferably 0.5 to 10 parts by weight per 100 parts by weight of the prepolymeric or monomeric syrup. Sufficient hardener should be employed to 5 achieve cure of the epoxy resin. -Because there are many points in, for example, an automotive painting cycle at which the sheet material may be used, the heat to which the sheet material is exposed may be insufficient to fully cure the epoxy resin. In `
these cases, it may be advantageous to add an accelerator to the prepolymer 10 blend, so the resin may fully cure at a lower temperature, or may fully cure when exposed to heat for shorter periods. Imidazoles and urea derivatives are particularly preferred in the practice of the present invention for use as accelerators because of their ability, as shown by the examples herein, to extend the shelf life of acrylic based materials containing uncured epoxy resin.15 The most presently preferred imidazoles for use in the present invention are 2 ,4-diamino-6-(2 ' -methyl-imidazoyl)-ethyl-s-triazine isocyanurate, 2-phenyl-4-benzyl-5-hydoxymethylimidazole, hexakis (imidazole) nickel phthalate and ;
toluene bis-dimethylurea. Such an accelerator may be employed typically in an amount of up to about 20 parts by weight per 100 parts by weight of the ~-;
20 prepolymeric or monomeric syrup.
In order to provide a sheet material exhibiting the desired flow characteristics in response to heating it may be desirable to include a chain transfer agent in the starting materials used for preparing the thermosettable pressure-sensitive adhesive. Such inclusion facilitates obtainment of a lower 25 molecular weight acrylic polymer having a broader distribution of molecular :
- weight.
Other useful materials which can be blended inta the thermosettable pressure-sensitive adhesive include, but are not limited to, ;
fillers, pigments, fibers, woven and nonwoven fabrics, foaming agents, 30 antioxidants, sta~ilizers, fire retardants, and viscosity adjusting agents. -4~7 2 1 1 8 0 1 7 PCI /US93/03469 ~

The sheet material employed in the method of the present invention is preferably prepared by premixing together the photopolymerizable monomers and the photoinitiator. 1his premix is then partially polymeri~ed to a viscosity in the range of from about 500 cps to about 5,000 cps to achieve a 5 coatable syrup. Alternatively, the monomers may be mixed with a thixotropic agent such as fumed hydrophilic silica to achieve a coatable thickness. The other ingredients such as the epoxy resin and heat-activatable hardener are thenadded to the syrup prior to photo-polymerization.
The above composition is coated onto a flexible carrier web, 10 preferably a silicone release liner which is transparent to ultraviolet radiation, and polymerized in an inert, i.e., a substantially oxygen free, atmosphere, e.g., a nitrogen atmosphere. A sufficiently inert atmosphere can be achieved by covering a layer of the photoactive coating with a plastic film which is substantially transparent to ultraviolet radiation, and irradiating through thatfilm in air as described in U.S. Pat. No. 4,181,752 (Martens et al.). The liners ;-may then be removed when it is desired to use the resulting sheet material in the method of the invention.
The method of the present invention has a number of applications in industry. One utility of the method is in the automotive industry where it 20 can be utilized in a process to seal metal joints in automobiles. By this process, one first prepares the sheet material such as by the above-described process.
Subsequently, the sheet material would be applied over the joint to be sealed.
Complete sealing and bonding would be obtained because the sheet material ` flows prior to hardening. As a result of the controlled flow of the edges of the 25 sheet material, an aesthetic surface appearance is achieved. The exposed surface of the hardened sheet material can then be painted or otherwise decorated to match the automobile body.
An altemative application of the method of the invention is in the application of emblems or insignia or design elements to surfaces such as an 30 automobile body. An example of an emblem or insignia is a logo of an automobile manufacturer. An example of a design element is trim to enhance wo 93~23487 Pcr/uss3/03469 and highlight auto body curvature and to provide protection to the primed metal -substructure without the need for complex metal stamping to obtain the shape.
In such a method, the sheet material is configured initially in the shape of rthe emblem or insignia or design elements desired such as by die-cutting. Practice , 5 of the method of the invention thereby provides an aesthetically pleasing emblem or insignia having smooth transition lines relative to the surface to which it has been bonded.
In still another application of the method of the invention, the substrate to which the sheet material is initially adhered is a temporary substrate 10 such as a disposable liner. Subsequent to hardening of the sheet material in a fashion to provide the controlled flow of its edges, the hardened sheet material -may be fastened (e.g., adhered) to the permanent substrate through the use, for example, of an adhesive system distinct from the sheet material itself since thehardened sheet material may be substantially devoid of pressure-sensitive 15 adhesive properties. In this manner, the method of the invention may be used to apply configured, hardened sheet materials such as signs to surfaces such as wooden doors.
The invention is further illustrated by the following non-limiting examples in which all parts are expressed as parts by weight unless otherwise 20 indicated.

Test Methods 250F. Shear Creep Flow Test: A ~ inch2 piece of tape is placed at the top of a 2 inch by 6 inch anodized aluminum panel. A 2 inch by 25 1 inch piece of anodized aluminum weighing approximately 5.5g is placed on top of the tape and parallel to the base panel; contact is made by rolling twicewith a 15 lb. wheel. A line is drawn to mark the initial position of the small aluminum piece. The panel is then hung vertically on a rack and placed in a 250F. oven for 30 minutes. After this time, the rack is removed and allowed 30 to cool. When cool, the panel is removed from the rack and the position of the small aluminum piece of marked by drawing a line. The difference between ;

:

W0 93/23487 21 il 8 b I 7 PCr/US93/03469 i - .
9 :~:
the initial position and the position after heating is measured in centimeters. If the tape is very meltable and the small aluminum piece falls off, a reading of > 15 cm will be noted.

S Melt Flow Visual Observation: A 1 inch2 piece of tape is placed on a steel panel which has been electro-coated with paint primer, such as PPG
ED-3150 (from Advanced Coatings Technology, lnc., Michigan). The panel with tape is placed horizontally in a 250F. oven for 30 minutes, then removed and allowed to cool to room temperature. Visual examination of the tape is 10 made based on the following criteria:
1 = no flow, tape has square edges.
2 = some flow, tape has slightly rounded edges.
- 3 = more flow, tape has very rounded edges.
4 = more flow, tape is starting to become liquid.
5 = most flow, tape has become liquid.

EXAMPLE 1 ~`
One hundred parts of a mixture of n-butyl acrylate/N-vinyl . . .
caplolactam, with a monomer ratio of 80/20, was blended with 0.04 parts of 20 Irgacure~65 1 photoinidator and photopolymerized with an ultraviolet (UV) light source~(Sylvania F20T 12BL) under a constant nitrogen purge to a viscosity of about 3000 cps. An addidonal 0.1 part of IrgacurerY65 l (available from Ciba-. .
Geigy Corpor~n), 50 parts of Epon~1001 (diglycidyl ether of bisphenol Aavailable &om Shell Chemical Co.), 30 parts of Epon'Y828 (diglycidyl ether of 25 bisphenol A available from Shell Chemical Co.), 5.94 parts of micronized dicyandiamide ~hardener, 5.04 parts of toluene bis-~dimethyl urea (Omicure~24 ;
available from Omicron Chemicals lnc.), and 0.05 parts of 3-mercaptopropionic acid as a chain tr~nsfer agent were added. The mixture was thoroughly mixed ~ on a labQ~atory mixer for about 15 minutes and allowed to slowly roll on a ball - ~ 30 mill mixer for approximately 16 hours. The mixture was then hlife coated at a `
thickness of 40 mil (1.016 millimeters) onto a transparent silicone coated .

WO 93~23487 2 1 1 8 0 1 7 Pcr/uss3/o3469 ` ~

polyester liner having a thickness of about 0.05 millimeters and covered with a second similar polyester liner. The coated mixture was photopolymerized using UV light sources above and below the tape having intensities of 1.82 mWatts/cm2 above and 1.73 below at the web as measured using a Uvirad 5 radiometer (Model No. VR365CH3) from E.I.T. (Electronic Instrumentation &
Technology, Inc., Sterling, VA). The total UV energy was 450 mJoules/cm2. ~-The liners were removed from the adhesive sheet material obtained above and the sheet material was adhered to a steel sheet. The re~ulting laminate was then placed for twenty minutes in an oven maintained at 10 270F. During this heating cycle the edges of the sheet material flowed to -~ ~
provide smooth transition lines between the apex of the sheet material and the ;
steel sheet. ~
..

A sheet material was prepared according to the procedures of Example 1 and was converted into a tape having a width of one-half inch (1.27 cm). The tape was placed in a recessed lap joint which was prepared by spot welding two pieces of steel together. A base coat ("NHU90394R" available from PPG, Pittsburg, PA) was applied directly over the tape and the lap 20 joint/tape laminate was placed in an oven maintained at 270F. for 20 minutes.
A clear coat (DCT 5000 from PPG, Pittsburg, PA) was then applied and the lap joint/tape laminate was thereafter run through a second baking cycle as above.
The resulting sealed lap joint had an aesthetically pleasing, painted appearance.
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An adhesive sheet material was prepared using the ingredients (and amounts thereof) and procedures described in Example 1 except that no chain transfer agent was included, and the amounts of micronized `
dicyandian~ide hardener and toluene bis-dimethyl urea added to the coatable syrup were 10.8 parts and 9.02 parts, respectively.

W0 93/23487 ~2 1 1 8 0 1 7 Pcr/US93/03469 The sheet material was converted to a tape which was then adhered to a recessed lap joint and processed all as described in Example 2.
During the process, the edges of the tape flowed, but to a lesser extent th?n -:
resulted in Example 2, to provide smooth transition lines between the apex of 5 the tape and the recessed lap joint.

The components which are listed in Table lA were mixed together to prepare three formulations which varied only in the type of 10 nitrogen-containing copolymerizable monomer used. The ratio of the butyl acrylate to the nitrogen-containing copolymerizable monomer in the syrup was varied so as to maintain the nitrogen-containing monomer on an equivalent molar basis. All amounts are amounts by weight. -;~ ~ Syruping: The acrylate components were blended with ~
15 photoinitiator and photopolymerized with an ultraviolet (UV) light source under ~.
a constant nitrogen purge to produce partially polymerized "syrups". These syrups were then blended with the epoxy, epoxy curatives and other ingredients and were rnixed until a solution was achieved.
Coatin~: These resuldng formulations were degassed in a 20 vacuum and fed into the nip of a knife coater between two transparent, biaxially-oriented polyethylene terphthalate films, the facing surfaces Qf which `
had a sUicone release coating. The knife coater was adjusted to provide a coa:ting thicbness of approximately 40 mils. The coadngs emerging from the bnife coater were irradiated with a UV light source, exposing each side of the 2 5 coatings to a total energy of 223 mj/cm2 at an intensity of 1.29 mW/cm2, to give pressure-sensitive transfer tapes. The properties of these tapes are shown in Table lB.

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W093/23487 2ll8nl7 PCr/US93/03469 TABLE lA
l l . ~.
SYRU~S Syrup A Syrup B Syrup C ¦ ~ I
S ~
Butyl acrylate (BA) 76 78 72 _ N-Vinyl pyrrolidone (NVP) 24 N,N-Dimethylacrylamide (NNDMA) 22 l ~, N-Vinyl caprolactam (NVC) 28 l I
Esacure~ KB-1 (benzil dimethyl ketal 0.04 0.04 0.04 from Sartomer) ..
Viscosity (cps) 2160 2000 2320 ,'~:
FORMULATIONS ¦ EXAMPLE 4 EXAMPLE S EXAMPLE 6 ¦

¦ Syrup A 100 ~:~
¦ Syrup B ~ 100 Syrup C 100 I .
¦ DER 3311Epon 1001F (50/50) 80 80 80 ¦ Esacure~ KB-I 0.1 0.1 0.1 ¦ Dicya~ldiamide 4.2 4.2 4.2 ¦ He~akis (imidazole) nickel phthalate 2.1 2.1 2.1 Aerosil R-9~2 (Dog~) 2 2 2 ¦ ~
I i~`.
F-80ED (polymeric microspheres 1.2 1.2 1.2 ¦
~from Malsumoto) I ;
~ , , ~. ~

WO 93/23487 2 1 1 8 ~ 1 7 ` PCI'/l)S93/03469 :

TABLE lB

PROPERTIES EXAMPLE 4 EXAMPLE S EXAMPLE 6 ¦
!
S Te~sile Strength 83 5 95 I
(uncured~, psi I
% Elongation (uncured) 1081 981 710 % Gel (EtOAc ~t 24 hr), 95 Sample partially 87 ~
(uncured) (No sample dissolved (No sample ¦
dissolution) dissolution) I
Tensile Strength, psi700 215 j 593 ;
(cured:: 140 C ~ 30 min) Ii .. :
% Elongation 55 313 52 (cured: 140 C ~ 30 min) 1 :
I ..
Dynamic Shear off 414 235 441 ¦
Alumi~um, psi l (cured: 140 C ~ 30 min) l ::
, ._ ~ 20 EXAMPLE 7 :As an additional characterization of these systems, the cured transfer tapes (140 C for 30 min) of Examples 4-6 were submitted for analysis .
by transmission electron microscopy. All the samples showed epoxy domains within a continuous acrylate phase, however, the average size of the majority of~: ~25 those epoxy domains was much larger (0.75 microns) for the Example 5 sample :than for the Exarnple 4 sample (0.18 microns) or the Example 6 sample (0.25 microns).
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The components listed in Table 2A were mixed together to :~ prepare four formulations which differed in the non-polar monomer used (BA ~.:
or IOA), and the nitrogen-containing monomer used (NNDMA or NVC). The formuiations were syruped and coated with the procedure described in l;
:35 Examples 4-6. The coated mixture was photopolymerized using W light :

. .. .... ...... .. ..... .

WO 93/23487 2 1 1 8 ~ 1 7 Pcr/US93/03469 sources (positioned above and below the tape) having intensities ~f 1.1 mW/cm2 to 2.5 mW/cm2. The total UV energy was 797 mJ/cm2. The properties of these tapes are shown in Table 2B.

: S
TABLE2A `.
.:`.
: . , :

SYRUPS Syrup A Sgrup B Syrup C ¦Syrup D ~
~ ;.:' Butyl acrylate 80 80 : lsoOctyl acrylate . 80 80 -;
N,N- 20 20 Dimethylacrylamide N-Vinyl prolactam 20 20 ¦ ~
:: ~ Esacu~ KB-1 0.04 0.04 0.04 0.04 ¦ . .`
~: ~ : : ...
Viscosity (cps) ~ 36 264 8 484 I ~
1~ : :' FORM~LATIONS: EXAM~LE EXAM~LE EXAM~LE EXAMPLE
: 8 9 10 11 '`
~ I I ;, ¦~ Syrup A 100 .
: ~ Syrup B .. 100 I .I I ~
¦ Syrup C ~ 1 100 .
; ¦ Syrup D : 100 ¦
:~ 25 ¦~ Epon 828 30 30 30 30 I i~
:: ¦ Epon 1001F 50 50 S0 50 I . .
Esllcure KB-I 0.2 0.2 0~2 0.2 Dicyandiamide 6 6 i 6 Toluene diisocyanato S S S S
30 1 ~ L I . ~

- .:

WO 93/23487 . ; ' PCI /US93/03469 TABLf: 2B
. _ EXAMP~EEXAMPLE EXAME~E EXAMPLE ~. -:

250F. Shear 3.7 > 15 1.5 I ~.
Creep Flow (cm) Mellability Visual 3 3 3 2 .-Examination ~ . .
(scale 1-5) 1::
l .:
::

EXAMPLES 12-16 ~:
The components listed in Table 3A were mixed together to prepare five formulations with increasing amounts of NNDMA in combination 15 with NVC in the syrup. The formulations were syruped and coated using the procedure described in Examples 4-6. The coated mixture was photopolymerized using UV light sources (positioned above and below the tape) :
having intensities of 1.1 mW/cm2 to 2.5 mW/cm2. The total UV energy was 396 nJ/cm2. The properties of these tapes are shown in Table 3B. `

WO 93/23487 2 1 1 8 PCr/US93/03469 ~
017 j ~

_ _ _ ,:
FORMULATION EX. 12 EX. 13 EX. 14EX. 15 EX~ 16 ~
S
_ ~
Syrup A:
BA/NVC/NNDMA/ICB-l 100 (76/2410/0 04) I . _ .-:
Syrup B- 100 ¦
(76/18/6/0.04) I
I I :.
Symp C: I :.:
BA/NVC/NNDMA/KB-l 100 I (76/12/12/0.04) 15 Syrup D:
BA/NVC/NNDMA/KB-l 100 (76/611810.04) I
Syrup E: ¦
BA/NVC/NNDMA/KB-l _ 100 I ;
20 I (76/0124/0.04) I ,.
Epon 828 30 30 30 30 30 l I I .~.
¦ Epon 1001F 1 50 50 50 S0 50 ¦ Esacure~ l 0.1 0.1 0.1 0.1 0.1 ¦ Dicyandiamide 1 6 6 6 6 6 TDI-urea 2 2 2 ` 2 2 l ',.' WO 93/23~87 2 1 1 8 0 1 7 PCl /US93/03469 , ~

1~
PROPERTIES ¦ EX. 12 ¦EX. 13 ¦EX. 14 ¦EX. 15 ¦EX. 16 ¦
i.:
250F Shear Creep Flow, cm 1.6 3.4 4.1 5.5 6.1 ~ ~
I . _ . .:. .
Meltability Visual Evaluation I 2 3 3 3 (scale 1-5) I I .-,,, Dynamic Shear, ED-3150 -coated steel2 (cured: 120C. ~ 1060 791 662 354 267 130min),psi I ,.
T-peel, ED-3150 coated steel 45 43 38 26 --(cured: 120C. ~ 30 min), psi 90 degree peel (uncured) 20 m n. dwell off ED-3150, IblO.S 4.3 7.9 8.4 9.1 8 .6 I mcb Electro-coated steel panels coated with paint primer -~ `
20 available as ED-3150 from PPG Industries. `
'.`' `

A formulation was prepared generally according to the procedures of the previous Examples using the ingredients (and amounts) listed 25 in Table 4 below.
. . .

~ ' W093/23487 2ll~ol 7 PCr/US93/03469 TABLE 4 ;

S INGREDIENT AMOUNT
` :,`' BA/NNDMA (80/20) 100 Irgacure~65 1 0.14 Epicote~1001 (from Shell Chemical Co.) 85 1:
. :
¦ Epon~828 _IS i Wlliton~SB (calcium carbonate from Shiraishi Kogyo 20 Kaisha, Ltd.) `:
I I j.. , : Dicyandiamide 7 . .
I I ...
2,4-Diamin~6-[2'-(me~hylimidazoyl)-(1)']- 4 ethyl-S-tnazine isocyanurate adduct ¦ (from Shikoku Chemical Co., Ltd.) ~

¦ Glycidyl methacrylate 3 ¦
3-mercaptopropionic acid 0.02 ..~

' .
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Claims (10)

WHAT IS CLAIMED IS:

1. A method for imparting topographical or protective features to a permanent substrate comprising the steps of:
a) providing a dissevered, hardenable sheet material having first and second major surfaces, comprising a latent thermosettable pressure-sensitive adhesive throughout a major portion of its thickness, and exhibiting pressure-sensitive adhesive properties at said first major surface;
b) contacting and adhering said first major surface of said sheet material to said permanent substrate or a temporary substrate leaving said second major surface of said sheet material exposed;
c) substantially thermosetting and substantially hardening said sheet material in a manner permitting initial, controlled mass flow of the sheet material substantially in its thickness direction to provide a substantially smooth transition between said second surface of said sheet material and said permanent substrate or said temporary substrate to which it has been adhered; and d) in the event said hardened sheet material is adhered to said temporary substrate, removing said hardened sheet material therefrom and thereafter fastening said first major surface of said sheet material to said permanent substrate.

2. A method according to Claim 1, wherein step b) involves the contacting and adhering of said first major surface of said sheet material to said permanent substrate.

3. A method according to Claim 1, wherein step b) involves the contacting and adhering of said first major surface of said sheet material to said temporary substrate.

4. A method according to Claim 1, wherein step c) is accomplished by heating said sheet material.

5. A method according to Claim 4, wherein step c) is accomplished by heating said sheet material to a temperature sufficient to decrease its modulus and thereby permitting said controlled mass flow, followed by heating said sheet material to a higher temperature resulting in substantially thermosetting and substantially hardening said sheet material.

6. A method according to Claim 5, wherein step c) is accomplished by a continuous increase in temperature of said sheet material.

7. A method according to Claim 1, further comprising the step of painting said second major surface of said sheet material prior to step c).

8. A method according to Claim 1, further comprising the step of painting said second major surface of said sheet material subsequent to step c).

9. A method according to Claim 1, wherein said thermosettable pressure-sensitive adhesive exhibits pressure-sensitive adhesive properties at ambient temperature.

10. A method according to Claim 1, wherein said sheet material comprises said thermosettable pressure-sensitive adhesive throughout substantially its entire thickness.