U.S. patent application number 12/745852 was filed with the patent office on 2010-09-30 for laminating adhesive.
This patent application is currently assigned to Mitsui Chemicals, Inc.. Invention is credited to Akihiro Imai, Takeshi Osaki, Shigetoshi Sasano.
Application Number | 20100249360 12/745852 |
Document ID | / |
Family ID | 40717613 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100249360 |
Kind Code |
A1 |
Imai; Akihiro ; et
al. |
September 30, 2010 |
LAMINATING ADHESIVE
Abstract
[Solution to Problem] The laminating adhesive of the present
invention includes a polyisocyanate component (A) and a polyol
component (B), wherein the polyisocyanate component (A) contains a
polyisocyanate (A1) that does not contain an aromatic ring, and the
polyol component (B) contains a macropolyol (B1) that does not
contain an aromatic ring but contains a cyclohexane ring.
Inventors: |
Imai; Akihiro; (Chiba,
JP) ; Osaki; Takeshi; (Chiba, JP) ; Sasano;
Shigetoshi; (Chiba, JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Mitsui Chemicals, Inc.
|
Family ID: |
40717613 |
Appl. No.: |
12/745852 |
Filed: |
November 27, 2008 |
PCT Filed: |
November 27, 2008 |
PCT NO: |
PCT/JP2008/071552 |
371 Date: |
June 2, 2010 |
Current U.S.
Class: |
528/59 ;
528/85 |
Current CPC
Class: |
C08G 18/6674 20130101;
C08G 18/44 20130101; C08G 18/4216 20130101; C09J 175/06 20130101;
C08G 18/4238 20130101; C08G 18/003 20130101; C08G 18/3212 20130101;
C08G 18/755 20130101; C08G 18/792 20130101; C08G 18/757 20130101;
C08G 18/79 20130101; C08G 18/664 20130101; C08G 18/4854 20130101;
C08G 18/4615 20130101 |
Class at
Publication: |
528/59 ;
528/85 |
International
Class: |
C08G 18/32 20060101
C08G018/32 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2007 |
JP |
2007-312542 |
Claims
1. A laminating adhesive comprising: a polyisocyanate component (A)
and a polyol component (B), wherein the polyisocyanate component
(A) contains a polyisocyanate (A1)) that does not contain an
aromatic ring, and the polyol component (B) contains a macropolyol
(B1) that does not contain an aromatic ring but contains a
cyclohexane ring.
2. The laminating adhesive according to claim 1, wherein the
cyclohexane ring concentration relative to the solid content of the
polyisocyanate component (A) and the polyol component (B) in total
is 2.5 mmol/g or less.
3. The laminating adhesive according to claim 1, wherein the
macropolyol (B1) is a polyurethane polyol (B1-1') obtained by
reaction of a crystalline polyol (B1-1a') that does not contain an
aromatic ring and is crystalline at normal temperature with a
polyisocyanate (B1-1b) that does not contain an aromatic ring but
contains a cyclohexane ring.
4. The laminating adhesive according to claim 3, wherein the
crystalline polyol (B1-1a') contains a crystalline polycarbonate
diol that is crystalline at normal temperature.
5. The laminating adhesive according to claim 4, wherein the
crystalline polycarbonate diol that is crystalline at normal
temperature has a number average molecular weight of 1000 or
less.
6. The laminating adhesive according to claim 1, wherein the
polyisocyanate component (A) does not contain a derivative of
isophorone diisocyanate.
7. The laminating adhesive according to claim 6, wherein the
macropolyol (B1) is a polyurethane polyol (B1-1') obtained by
reaction of a polycarbonate diol that has a number average
molecular weight of 5000 or less, does not contain an aromatic
ring, and is crystalline at normal temperature, with a
polyisocyanate (B1-1b) that does not contain an aromatic ring but
contains a cyclohexane ring.
8. The laminating adhesive according to claim 1, wherein the
laminating adhesive is used for laminating outdoor composite
sheets.
Description
TECHNICAL FIELD
[0001] The present invention relates to a laminating adhesive, and
more particularly, the present invention relates to a laminating
adhesive suitably used for laminating composite sheets that are
used under an outdoor environment and a similar environment
thereof.
BACKGROUND ART
[0002] Composite sheets are manufactured by laminating a plurality
of sheet materials using an adhesive: the sheet materials are
selected from various plastic films, metal foils such as aluminum
foils, metal deposited films, silica deposited films, and the
like.
[0003] For the adhesive used for laminating composite sheets, a two
component-type polyurethane adhesive in which a polyisocyanate
component and a polyol component are mixed has been widely used,
because of its superior adhesion performance.
[0004] As such a two component-type polyurethane adhesive, for
example, there has been proposed a two component-curing laminating
adhesive composition in which a polyol component is used as a main
component, and a polyisocyanate component is used as a curing agent
(for example, see Patent Document 1 below).
[0005] The composite sheets are used for outdoor sheets that are
used under an outdoor environment, for example, leisure sheets,
tents, plastic green houses, sheets for porch, rain coats,
umbrellas, hoods, waterproof cloth, sheets for covering
automobiles, sheets for covering building materials, and back
sheets for solar batteries.
[0006] Patent Document 1: Japanese Unexamined Patent Publication
No. 2003-129024
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0007] However, when the two component-curing laminating adhesive
composition described in the above Patent Document 1 is used for a
composite sheet used under an outdoor environment (in the
following, referred to as an outdoor composite sheet), a problem of
adhesive yellowing with age occurs due to solar ultraviolet
radiation, or of delamination is caused from adhesive deterioration
by rainwater, sunlight irradiation heat, and ultraviolet rays.
[0008] An object of the present invention is to provide a
laminating adhesive that suppresses the yellowing with age; has
excellent durability under rainwater, sunlight irradiation heat,
and ultraviolet rays; and even brings out excellent adhesion
performance.
Means for Solving the Problem
[0009] The laminating adhesive of the present invention includes a
polyisocyanate component (A) and a polyol component (B), wherein
the polyisocyanate component (A) contains a polyisocyanate (A1))
that does not contain an aromatic ring; and the polyol component
(B) contains a macropolyol (B1) that does not contain an aromatic
ring but contains a cyclohexane ring.
[0010] Furthermore, in the laminating adhesive of the present
invention, it is preferable that the cyclohexane ring concentration
relative to the solid content of the polyisocyanate component (A)
and the polyol component (B) in total is 2.5 mmol/g or less.
[0011] Furthermore, in the laminating adhesive of the present
invention, it is preferable that the macropolyol (B1) is a
polyurethane polyol (B1-1') obtained by reaction of a crystalline
polyol (B1-1a') that does not contain an aromatic ring and is
crystalline at normal temperature with a polyisocyanate (B1-1b)
that does not contain an aromatic ring but contains a cyclohexane
ring; it is more preferable that the crystalline polyol (B1-1a')
contains a crystalline polycarbonate diol that is crystalline at
normal temperature; and it is more preferable that the crystalline
polycarbonate diol that is crystalline at normal temperature has a
number average molecular weight of 1000 or less.
[0012] Furthermore, in the laminating adhesive of the present
invention, it is preferable that the polyisocyanate component (A)
does not contain a derivative of isophorone diisocyanate, and in
such a case, it is preferable that the macropolyol (B1) is a
polyurethane polyol (B1-1') obtained by reaction of a crystalline
polycarbonate diol that has a number average molecular weight of
5000 or less, does not contain an aromatic ring, and is crystalline
at normal temperature, with a polyisocyanate (B1-1b) that does not
contain an aromatic ring but contains a cyclohexane ring.
[0013] Furthermore, the laminating adhesive of the present
invention is preferably used for laminating outdoor composite
sheets.
Effects of the Invention
[0014] The laminating adhesive of the present invention brings out
excellent adhesion performance while suppressing the yellowing with
age due to solar ultraviolet radiation, and suppresses
deterioration by rainwater, sunlight irradiation heat, and
ultraviolet rays, so that occurrence of delamination is prevented.
Therefore, the laminating adhesive of the present invention is
suitable for laminating outdoor composite sheets.
EMBODIMENT OF THE INVENTION
[0015] A laminating adhesive of the present invention is a two
component-type polyurethane adhesive, and contains a polyisocyanate
component (A) and a polyol component (B).
[0016] In the present invention, the polyisocyanate component (A)
contains a polyisocyanate (A1) that does not contain an aromatic
ring, that is, alicyclic polyisocyanate, aliphatic polyisocyanate,
and/or derivatives thereof.
[0017] Examples of the alicyclic polyisocyanate include, alicyclic
diisocyanate such as 1,3-cyclopentene diisocyanate, 1,4-cyclohexane
diisocyanate, 1,3-cyclohexane diisocyanate,
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone
diisocyanate; IPDI), 4,4'-, 2,4'- or 2,2'-dicyclohexylmethane
diisocyanate or mixtures thereof (H.sub.12MDI),
methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane
diisocyanate, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or
mixtures thereof (H.sub.6XDI), and norbornane diisocyanate
(NBDI).
[0018] Examples of the aliphatic polyisocyanate include aliphatic
diisocyanate such as trimethylene diisocyanate, tetramethylene
diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene
diisocyanate, 1,2-, 2,3- or E3-butylenediisocyanate, and 2,4,4- or
2,2,4-trimethylhexamethylene diisocyanate.
[0019] Examples of the derivatives of the alicyclic polyisocyanate
and the aliphatic polyisocyanate include multimers (dimers,
trimers, pentamers, septamers, etc.) of the above-described
polyisocyanate (A1) (that is, alicyclic polyisocyanate and/or
aliphatic poly isocyanate); a biuret-modified substance of the
above-described polyisocyanate (A) (for example, biuret-modified
polyisocyanate produced by reaction of the above-described
polyisocyanate (A1) with water); an allophanate-modified substance
of the polyisocyanate (A1) (for example, allophanate-modified
polyisocyanates produced by reaction of the above-described
polyisocyanate (A1) with monol or polyhydric alcohol (described
later)); a polyol-modified substance of the polyisocyanate (A1))
(for example, polyol-modified polyisocyanates produced by reaction
of the polyisocyanate (A1)) with polyhydric alcohol (described
later)); a urea-modified substance of the polyisocyanate (A1) (for
example, urea-modified polyisocyanate produced by reaction of the
polyisocyanate (A1) and diamine); oxadiazinetrione (for example,
oxadiazinetriones produced by reaction of the polyisocyanate (A1))
and carbon dioxide); and a carbodiimide-modified substance of the
polyisocyanate (A1) (carbodiimide-modified polyisocyanates produced
by decarboxylation condensation reaction of the polyisocyanate
(A1)).
[0020] Preferable examples of the polyisocyanate that does not
contain an aromatic ring include IPDI, H.sub.12MDI, H.sub.6XDI,
NBDI, HDI, and derivatives thereof.
[0021] In the present invention, the polyol component (B) contains
a macropolyol (B1) that does not contain an aromatic ring but
contains a cyclohexane ring.
[0022] Examples of the above-described macropolyol (B1) include a
polyurethane polyol (B1-1) that is obtained by reaction of a polyol
(B1-1a) that does not contain an aromatic ring with a
polyisocyanate (B1-1b) that does not contain an aromatic ring but
contains a cyclohexane ring; and a polyester polyol (described
later) that contains alicyclic polycarboxylic acid (described
later) and/or alicyclic diol (described later).
[0023] Examples of the polyol (B1-1a) that does not contain an
aromatic ring include a polyester polyol that does not contain an
aromatic ring, a polycarbonate polyol that does not contain an
aromatic ring, and a polyether polyol that does not contain an
aromatic ring.
[0024] Preferably, the polyol (B1-1a) that does not contain an
aromatic ring is a crystalline polyol (B1-1a') that does not
contain an aromatic ring and is crystalline at normal temperature,
such as a crystalline polyester polyol that docs not contain an
aromatic ring, a crystalline polycarbonate polyol that does not
contain an aromatic ring, and a crystalline polyether polyol that
does not contain an aromatic ring. More preferably, the polyol
(B1-1a) that does not contain an aromatic ring is a crystalline
polycarbonate polyol that does not contain an aromatic ring.
[0025] The crystalline polyol (B1-1a') (crystalline polyester
polyol, crystalline polycarbonate polyol, and crystalline polyether
polyol) refers to a polyol that is not in a liquid state (liquid or
fluid) at normal temperature but in a solid state at normal
temperature.
[0026] The above-described polyester polyol can be obtained, for
example, by a condensation reaction between a polybasic acid
selected from aliphatic polycarboxylic acid and alicyclic
polycarboxylic acid, and a polyhydric alcohol selected from
aliphatic diol, alicyclic diol, and polyfunctional polyol; or by a
transesterification reaction between an alkyl ester of a polybasic
acid and a polyhydric alcohol.
[0027] Examples of the aliphatic polycarboxylic acid include
succinic acid, glutaric acid, adipic acid, pimelic acid, cork acid,
azelaic acid, sebacic acid, dodecanedioic acid, and hydrogenated
dimer acid.
[0028] Examples of the alicyclic polycarboxylic acid include
hexahydrophthalic acid and tetrahydrophtalic acid.
[0029] Examples of the alkyl ester of the polybasic acid include
C1-4 alkyl esters of the above-described polybasic acids.
[0030] Examples of the aliphatic diol include ethylene glycol,
diethylene glycol, triethylene glycol, propylene glycol,
dipropylene glycol, tripropylene glycol, 1,4-butanediol,
1,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol,
1,5-pentanediol, 3-methyl-1,5-pentanediol,
2,4-diethyl-1,5-pentanediol, 2,2,4-trimethylpentane-1,3-diol,
1,6-hexandiol, neopentyl glycol, 1,5-heptanediol, 1,7-heptanediol,
3,3'-dimethylolheptane, 1,8-octanediol, 1,9-nonanediol,
1,10-decanediol, 1,11-undecanediol, 1,12-undecanediol,
12-hydroxystearyl alcohol, and a hydrogenated dimer diol.
[0031] Examples of the alicyclic diol include hydrogenated
bisphenol A, hydrogenated xylylenediol, cyclohexanediol, and
cyclohexanedimethanol.
[0032] Examples of the polyfunctional polyol include an aliphatic
polyol having three or more hydroxyl groups, such as glycerin,
trimethylolpropane, pentaerythritol, and sorbitol.
[0033] The condensation reaction or the transesterification
reaction can be performed according to a known process without any
particular limitation, and for example, the respective components
are charged, and the mixture was allowed to react at 150 to
240.degree. C. for 7 to 50 hours. Further, a known catalyst (for
example, a titanium-based catalyst, a zinc-based catalyst, etc.)
can be added for such reactions.
[0034] Examples of the above-described polyester polyol include
lactone-based polyester polyols such as polycaprolactone polyols
and polyvalerolactone polyols obtained by ring-opening
polymerization of lactones such as .epsilon.-caprolactone and
.gamma.-valerolactone using the above-described polyhydric alcohol
as an initiator.
[0035] Examples of the crystalline polyester polyol that does not
contain an aromatic ring include polyethylene adipate, polybutylene
adipate, and polyethylene butylene adipate with a number average
molecular weight of 1000 or more.
[0036] The above-described polycarbonate polyol can be obtained,
for example, by allowing phosgene, dialkyl carbonate, diallyl
carbonate, or alkylene carbonate to react using the above-described
polyhydric alcohol as an initiator under, for example, presence or
absence of a catalyst.
[0037] Examples of the crystalline polycarbonate polyol that does
not contain an aromatic ring include 1,6-hexanediol-base
polycarbonate diol with a number average molecular weight of 400 or
more.
[0038] The above-described polyether polyol can be obtained, for
example, by performing an addition reaction of alkylene oxides such
as ethylene oxide and/or propylene oxide using the above-described
polyhydric alcohol as an initiator. To be specific, examples
thereof include polyethylene glycol, polypropylene glycol, and
polyethylenepolypropylene glycol (random or block copolymer).
Further, polytetramethylene glycol obtained by ring-opening
polymerization of tetrahydrofurans is another example.
[0039] Examples of the crystalline polyether polyol that does not
contain an aromatic ring include polyethylene glycol,
polyethylenepolypropylene glycol (ethylene oxide-propylene oxide
block copolymer), and polyoxytetramethylene ether glycol with a
number average molecular weight of 1000 or more.
[0040] The number average molecular weight of the above-described
polyol (B1-1a) (the above-described polyester polyol, polycarbonate
polyol, and polyether polyol) is, for example, 100 to 5000.
[0041] In the case when a derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate is contained
as the polyisocyanate component (A) and when the polyurethane
polyol (B1-1') is prepared using the crystalline polycarbonate diol
that is in a crystalline state at normal temperature as the
above-described crystalline polyol (B1-1a') in the polyol component
(B), the number average molecular weight of the crystalline
polycarbonate diol is preferably 1000 or less. With the crystalline
polycarbonate diol having the number average molecular weight of
1000 or less, excellent transparency can be ensured even if the
derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate is contained
as the polyisocyanate component (A). There may be a case where
excellent transparency cannot be ensured when the number average
molecular weight of the crystalline polycarbonate diol exceeds 1000
and the derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate is contained
as the polyisocyanate component (A).
[0042] On the other hand, when the polyisocyanate component (A)
does not contain the derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate and the
polyurethane polyol (B1-1') is prepared using the crystalline
polycarbonate diol that is in a crystalline state at normal
temperature as the above-described crystalline polyol (B1-1a') in
the polyol component (B), the number average molecular weight of
the crystalline polycarbonate diol is preferably 5000 or less. When
the derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate is not
contained as the polyisocyanate component (A) and the number
average molecular weight of the crystalline polycarbonate diol is
5000 or less, excellent transparency can be ensured.
[0043] Transparency is an important property particularly for a
laminating adhesive that is used for transparent outdoor composite
sheets.
[0044] The number average molecular weight in the polyol component
(B) can be calculated by a known hydroxyl value measurement method
such as acetylation method or phthalic anhydride method and the
number of the functional group in the initiator or the raw
material.
[0045] As the above-described polyol (B1-1a), the above-described
polyhydric alcohol can also be used in combination with the
above-described polyester polyol, polycarbonate polyol, and/or
polyether polyol. For such a polyhydric alcohol, preferably, the
above-described alicyclic diol can also be used. When the
polyhydric alcohol is used together as the above-described polyol
(B1-1a), the polyhydric alcohol is used in an amount of, for
example, 0.1 to 50 parts by weight, or preferably 0.5 to 30 parts
by weight relative to 100 parts by weight of the above-described
polyester polyol, polycarbonate polyol, and/or polyether
polyol.
[0046] Examples of the polyisocyanate (B1-1b) that does not contain
an aromatic ring but contains a cyclohexane ring include the
above-described alicyclic polyisocyanate and derivatives thereof.
Preferable examples are IPDI, H.sub.12MDI, H.sub.6XDI, NBDI, and
derivatives thereof.
[0047] The polyurethane polyol (B1-1) can be obtained by subjecting
the above-described polyol (B1-1a) and the above-described
polyisocyanate (B1-1b) to urethane reaction at such a ratio that
the equivalent ratio (NCO/OH) of the isocyanate group in the
above-described polyisocyanate (B1-1b) relative to the hydroxyl
group in the above-described polyol (B1-1a) is smaller than 1, or
preferably 0.5 to 0.9. A known method may be used for the urethane
reaction.
[0048] Preferably, the polyurethane polyol (B1-1) is
polyurethanepolycarbonate polyol obtained by reaction of the
above-described polycarbonate polyol with the above-described
alicyclic polyisocyanate. More preferably, the polyurethane polyol
(B1-1) is polyurethane crystalline polycarbonate diol obtained by
reaction of the above-described crystalline polycarbonate diol with
alicyclic polyisocyanate.
[0049] Also, as described above, examples of the macropolyol (B1)
include a polyester polyol that contains alicyclic polycarboxylic
acid and/or alicyclic diol.
[0050] The hydroxyl group equivalent (OH equivalent) of the
above-described macropolyol (B1) is, for example, 1000 to 15000, or
preferably 1500 to 10000.
[0051] Other than the above-described macropolyol (B1), for
example, the above-described polyhydric alcohol may also be
contained in the polyol component (B). When the polyhydric alcohol
is contained as the polyol component, for example, 0.01 to 50 parts
by weight, or preferably 0.1 to 30 parts by weight of the
polyhydric alcohol relative to 100 parts by weight of the
macropolyol (B1) is contained.
[0052] A silane coupling agent may be mixed as necessary in one of
or both of the polyisocyanate component (A) and the polyol
component (B).
[0053] The silane coupling agent that may be used is represented,
for example, by the structural formula: R--Si.ident.(X).sub.3 or
R--Si.ident.(R')(X).sub.2 (wherein R represents an organic group
having a vinyl, epoxy, amino, imino, isocyanate, or mercapto group;
R' represents a lower alkyl group; and X represents a methoxy
group, an ethoxy group, or chlorine atom).
[0054] Specific examples of the silane coupling agent include
chlorosilanes such as vinyl trichlorosilane; aminosilanes such as
N-.beta.-(aminoethyl)-.gamma.-aminopropyltrimethoxysilane,
.gamma.-aminopropyltriethoxysilane,
N-.beta.-(aminoethyl)-.gamma.-propylmethyldimethoxysilane,
n-(dimethoxymethylsilylpropyl)ethylenediamine,
n-(triethoxysilylpropyl)ethylenediamine, and
N-phenyl-.gamma.-aminopropyl trimethoxysilane; epoxysilanes such as
.gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropyltriethoxysilane,
.beta.-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, and
di(.gamma.-glycidoxypropyl)dimethoxysilane; vinyl silanes such as
vinyltriethoxysilane; and isocyanate silanes such as
3-isocyanatopropyltrimethoxysilane, and
3-isocyanatopropyltriethoxysilane.
[0055] These silane coupling agents can be used alone or in
combination of two or more. The amount of the silane coupling agent
to be blended is, for example, 0.001 to 10 parts by weight, or
preferably 0.01 to 6 parts by weight per 100 parts by weight of the
total amount of the polyisocyanate component (A) and the polyol
component (B).
[0056] Further, additives such as epoxy resins, catalysts, coating
improving agents, leveling agents, antifoaming agents, stabilizers
including antioxidant and ultraviolet absorbers, plasticizers,
surfactants, pigments, fillers, organic or inorganic fine
particles, and antifungal agents may be blended with either or both
of the polyisocyanate component (A) and the polyol component (B) as
required. The amount of these additives to be blended is
appropriately determined according to the purposes and
applications.
[0057] When an epoxy resin is to be blended in order to improve
adherence, a hydrogenated bisphenol A epoxy resin may be blended to
further improve resistance to yellowing.
[0058] A laminating adhesive of the present invention is used as a
two component-type polyurethane adhesive in which the
polyisocyanate component (A) and the polyol component (B) are
blended. That is, in the laminating adhesive of the present
invention, the polyisocyanate component (A) and the polyol
component (B) are prepared separately in advance, and the
polyisocyanate component (A) and the polyol component (B) are
blended upon use, and applied on an adherend (sheet material). The
polyisocyanate component (A) and the polyol component (B) are
blended at such a ratio that the equivalent ratio (NCO/OH) of the
isocyanate group in the polyisocyanate component (A) relative to
the hydroxyl group in the polyol component (B) is, for example, 0.6
to 10, or preferably 0.8 to 6.
[0059] In the laminating adhesive of the present invention, the
concentration of the cyclohexane ring is, for example, 2.5 mmol/g
or less, or preferably, 2 mmol/g or less, or normally, 0.1 mmol/g
or more relative to the total solid content of the polyisocyanate
component (A) and the polyol component (B). When the concentration
of the cyclohexane ring exceeds 2.5 mmol/g, there may be a case
where excellent transparency as a laminating adhesive cannot be
ensured.
[0060] The laminating adhesive of the present invention is, to be
specific, prepared as a solvent-based or solventless type, and
mainly used for laminating composite sheets.
[0061] For example, when the laminating adhesive is prepared as a
solvent-based type, the polyisocyanate component (A) and the polyol
component (B) are diluted with an organic solvent and blended, and
the mixture is applied on one surface of the sheet material using a
solvent-type laminator. Then, after the solvent is evaporated, the
sheet is bonded to another sheet material, and then aged to be
cured at normal temperature or under heat. The amount of the
mixture applied is set in the range of, for example, about 2.0 to
10.0 g/m.sup.2 after evaporation of the solvent.
[0062] When the blending viscosity of the polyisocyanate component
(A) and the polyol component (B) is about 100 to 10000 mPas, or
preferably about 100 to 5000 mPas at normal temperature to
100.degree. C., the laminating adhesive can be prepared as a
solventless type.
[0063] For example, when the laminating adhesive is prepared as a
solventless type, the polyisocyanate component (A) and the polyol
component (B) are blended as is, and the mixture is applied on one
surface of the sheet material using a solventless-type laminator.
Then, the sheet is bonded to another sheet material, and then aged
to be cured at normal temperature or under heat. The amount of the
mixture applied is set in the range of, for example, about 0.5 to
5.0 g/m.sup.2.
[0064] The sheet material is not limited as long as the sheet can
be laminated as a composite sheet, and examples thereof include
metal foils and plastic sheets.
[0065] Examples of the metal that may be used to form the metal
foil include aluminum, stainless steel, iron, copper, and lead. The
thickness of the metal foil is usually 5 to 100 .mu.m, or
preferably 7 to 50 .mu.m.
[0066] Examples of the plastic that may be used to form the plastic
sheet include an olefinic polymer (for example, polyethylene and
polypropylene); a polyester polymer (for example, polyalkylene
terephthalate such as polyethylene terephthalate (PET) and
polybutylene terephthalate; polyalkylene naphthalate; and a
copolyester that contains these polyalkylene arylate units as main
components); a polyamide polymer (for example, nylon 6 and nylon
66); and a vinyl polymer (for example, polyvinyl chloride,
ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol
copolymer).
[0067] The plastic sheet may also include an inorganic layer formed
on at least one side thereof. The inorganic layer may be formed by
a vacuum evaporation, sputtering, or sol-gel technique. Examples of
the inorganic substance that may be used to form the inorganic
layer include an element such as titanium, aluminum, and silicon;
or an inorganic compound including these element(s) (for example,
oxide). Specific examples thereof include an aluminum-deposited
sheet and a silica-deposited sheet.
[0068] The thickness of the plastic sheet is usually 5 to 200
.mu.m, or preferably 10 to 150 .mu.m.
[0069] The surfaces of the metal foil and the plastic sheet may be
subjected to surface treatment, such as corona discharge treatment
and primer treatment. Further, the metal foil and the plastic sheet
may be appropriately printed.
[0070] The laminating adhesive of the present invention does not
contain an aromatic ring, and therefore yellowing with age can be
suppressed. Meanwhile, the laminating adhesive of the present
invention contains a cyclohexane ring, and therefore excellent
adhesive strength and mechanical strength can be ensured over a
long period of time. Then, the laminating adhesive of the present
invention can ensure excellent adhesion performance and
transparency.
[0071] Therefore, the laminating adhesive of the present invention
can suppress yellowing with age; has excellent durability under
rainwater, sunlight irradiation heat, and ultraviolet rays; and
even brings out excellent adhesion performance, so that occurrence
of delamination can be prevented. Therefore, the laminating
adhesive of the present invention is suitably used for laminating,
in particular, composite sheets used under an outdoor environment,
i.e., outdoor composite sheets.
[0072] To be more specific, the laminating adhesive of the present
invention is suitably used for laminating outdoor composite sheets
that are used under an outdoor environment, such as leisure sheets,
tents, plastic green houses, sheets for porch, rain coats,
umbrellas, hoods, waterproof cloth, sheets for covering
automobiles, sheets for covering building materials, and back
sheets for solar batteries.
EXAMPLES
[0073] Hereinafter, the present invention will be described in more
detail by way of Examples and Comparative Examples, but the present
invention is not limited thereto.
Preparation Example 1
Preparation of Polyol Component A
[0074] 130.5 g of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate and 345.3 g
of 1,6-hexanediol-base polycarbonate diol (manufactured by Ube
Industries, Ltd. solid at normal temperature) having a number
average molecular weight of 500 were stirred under a nitrogen gas
stream at 90 to 95.degree. C. and the mixture was subjected to
urethane reaction, to synthesize a polyurethane polyol. After
confirming that no NCO peak was found by IR measurement, 500 g of
ethyl acetate and 23.8 g of .gamma.-glycidoxypropyltrimethoxysilane
(KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.) were added
thereto, thereby obtaining a polyol component A having, a solid
content of 50 wt %.
Preparation Example 2
Preparation of Polyol Components B to M
[0075] Polyol components B to M were prepared in the same manner as
the method in Preparation Example 1, except that the components and
the mixing ratios as shown in Table 1 were used.
Preparation Example 3
Preparation of Polyol Component N
[0076] 330.68 g of isophthalic acid, 71.38 g of ethylene glycol,
and 359.31 g of neopentyl glycol were subjected to esterification
reaction at 180 to 220.degree. C. under a nitrogen gas stream.
After a predetermined amount of water was distilled off, 402.57 g
of sebacic acid was added thereto, and the resulting mixture was
subjected to esterification reaction at 180 to 220.degree. C., to
give a polyester polyol PE1 having a number average molecular
weight of about 2,500.
[0077] Then, 446.6 g of the polyester polyol PE1, 32.5 g of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate, 191.4 g of
ethyl acetate were stirred under a nitrogen gas stream at 90 to
95.degree. C. and the mixture was subjected to urethane reaction,
to synthesize a polyurethane polyol.
[0078] After confirming that no NCO peak was found by IR
measurement, 314.04 g of ethyl acetate, 2.15 g of diethylene
glycol, and 23.95 g of .gamma.-glycidoxypropyltrimetoxysilane
(KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.) were added
thereto, thereby obtaining a polyol component N having a solid
content of 50 wt %.
Preparation Example 4
Preparation of Polyol Component O
[0079] 735.19 g of adipic acid, 184.56 g of ethylene glycol, 83.02
g of neopentyl glycol, 200.79 g of 1,6-hexanediol were subjected to
esterification reaction under a nitrogen gas stream at 180 to
220.degree. C., to give a polyester polyol PE2 having a number
average molecular weight of about 5,500.
[0080] Then, 448 g of the polyester polyol PE2, 470.5 g of ethyl
acetate, 22.4 g of .gamma.-glycidoxypropyltrimetoxysilane (KBM403
manufactured by Shin-Etsu Chemical Co., Ltd.) were stirred at
50.degree. C. until the mixture became homogenous, to give a polyol
component O.
Preparation Example 5
Preparation of Polyol Component P
[0081] 468 g of 1,6-hexanediol-base polycarbonate diol
(manufactured by Ube Industries, Ltd., solid at normal temperature)
having a number average molecular weight of 3000, 491.5 g of ethyl
acetate, 23.4 g of .gamma.-glycidoxypropyltrimethoxysilane (KBM403
manufactured by Shin-Etsu Chemical Co., Ltd.) were stirred at
50.degree. C. until the mixture became homogenous, to give a polyol
component P.
Preparation Example 6
Preparation of Polyol Component Q
[0082] 136.3 g of 1,6-hexanediol, 92.4 g of neopentyl glycol, 95.6
g of ethylene glycol, 292.6 g of isophthalic acid, and 0.2 g of
zinc acetate were subjected to esterification reaction at 180 to
220.degree. C. under a nitrogen gas stream. After a predetermined
amount of water was distilled off, 85.8 g of adipic acid was added
thereto, and the resulting mixture was subjected to esterification
reaction at 180 to 220.degree. C., to give a polyester polyol PE3
having a number average molecular weight of about 10,000.
[0083] Then, 381.9 g of ethyl acetate, 45.3 g of a solution of
bisphenol A epoxy resin in ethyl acetate (YD-902LEA60 manufactured
by Tohto Kasei Co., Ltd.), 31.3 g of
.gamma.-glycidoxypropyltrimetoxysilane (KBM403 manufactured by
Shin-Etsu Chemical Co., Ltd.), and 1.1 g of phosphoric acid were
added thereto and stirred until the mixture became homogenous, to
give a polyol component Q.
Preparation Example 7
Preparation of Polyisocyanate Component A
[0084] TAKENATE A-3070 (manufactured by Mitsui Chemicals
Polyurethanes, Inc., a derivative of hexamethylene diisocyanate,
ethyl acetate solution, a solid content of 75 wt %) was prepared as
a polyisocyanate component A.
Preparation Example 8
Preparation of Polyisocyanate Component B
[0085] 124.38 g of Vestanat T 1890/100 (manufactured by Huls AG. a
derivative of
3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate) and 0.62 g
of dibutyltin dilaurate were dissolved in 375 g of ethyl acetate,
to prepare a polyisocyanate component B as a solution having a
solid content of 25 wt %.
Preparation Example 9
Preparation of Polyisocyanate Component C
[0086] TAKENATE D-120N (manufactured by Mitsui Chemicals
Polyurethanes, Inc., a derivative of 1,3-, and
1,4-bis(isocyanatomethyl)cyclohexane, ethyl acetate solution, a
solid content of 75 wt %) was prepared as a polyisocyanate
component C.
TABLE-US-00001 TABLE 1 Polyol Component A B C D E F G H I Poly-
Polyiso- IPDI 130.5 75.1 36.4 23.4 113.7 46.7 urethane cyanate
H.sub.6XDI 103.3 138.4 Polyol H.sub.12MDI 86.2 Polyol PCD-1 345.3
133.0 PCD-2 422.3 341.1 304.0 410.7 140.0 114.0 PCD-3 437.0 280.0
PCD-4 451.5 CHDM 43.0 65.8 82.2 PTG2000 PTG3000 C2090 PE1 Polyester
Polyol Diethylene Glycol KBM403 (parts/100 parts by 5 5 5 5 5 5 5 5
5 weight solid content) Solid Content (% by weight) 50 50 50 50 50
50 50 50 50 OH Equivalent 2412 3093 4551 5524 2044 1090 3177 3501
1034 (g/mol (solid content)) Cyclohexane Ring Concentration 1.174
0.647 0.330 0.211 1.548 1.988 0.630 0.428 2.61 (mmol/g(solid
content)) Benzene Ring Concentration 0 0 0 0 0 0 0 0 0
(mmol/g(solid content)) Viscosity (mPa S/25.degree. C.) 280 420
1790 1320 1160 200 1070 640 -- Polyol Component J K L M N O P Q
Poly- Polyiso- IPDI 34.0 45.3 32.5 urethane cyanate H.sub.6XD1 23.4
40.0 Polyol H.sub.12MDI Polyol PCD-1 PCD-2 PCD-3 218.5 PCD-4 468.0
CHDM PTG2000 218.5 PTG3000 451.5 C2090 452.9 457.6 PE1 446.6
Polyester Polyol PE2 PE3 Diethylene Glycol 2.15 KBM403 (parts/100
parts by 5 5 5 5 5 5 5 weight solid content) Solid Content (% by
weight) 50 50 50 50 50 50 50 60 OH Equivalent 5524 3773 11553 11421
6200 2950 1575 4600 (g/mol (solid content)) Cyclohexane Ring
Concentration 0.211 0.309 0.389 0.394 0.289 0 0 0 (mmol/g(solid
content)) Benzene Ring Concentration 0 0 0 0 1.76 0 0 3.04
(mmol/g(solid content)) Viscosity (mPa S/25.degree. C.) 1980 670
2430 2260 1500 76 92 500
[0087] Abbreviations in Table 1 are described in the following.
PCD-1: manufactured by Ube Industries, Ltd., 1,6-hexanediol-base
polycarbonate diol, number average molecular weight of 500, solid
at normal temperature PCD-2: manufactured by Ube Industries, Ltd.,
1,6-hexanediol-base polycarbonate diol, number average molecular
weight of 1000, solid at normal temperature PCD-3: manufactured by
Ube Industries, Ltd., 1,6-hexanediol-base polycarbonate diol,
number average molecular weight of 2000, solid at normal
temperature PCD-4: manufactured by Ube Industries, Ltd.,
1,6-hexanediol-base polycarbonate diol, number average molecular
weight of 3000, solid at normal temperature CHDM:
cyclohexanedimethanol PTG2000: manufactured by Hodogaya Chemical
Co., LTD., polytetramethyleneglycol, number average molecular
weight of 2000, solid at normal temperature PTG3000: manufactured
by Hodogaya Chemical Co., LTD., polytetramethyleneglycol, number
average molecular weight of 3000, solid at normal temperature
C-2090: manufactured by Kuraray Co., Ltd., polycarbonate diol,
number average molecular weight of 2000, liquid at normal
temperature
EXAMPLES AND COMPARATIVE EXAMPLES
[0088] Laminating adhesives were prepared by blending a polyol
component and a polyisocyanate component according to the
formulation and ratio shown in Table 2.
[0089] Table 2 also shows the cyclohexane ring concentration
(mmol/g) relative to the total (solid content) of the polyol
component and the polyisocyanate component.
Evaluation
1) Peel Test at 80.degree. C.
[0090] The laminating adhesives of Examples and Comparative
Examples were applied in an amount of about 5 g/m.sup.2 on a
treatment surface of a PET sheet (P-60 manufactured by Toray
Advanced Film Co Ltd., 16 microns), and after the solvent was
evaporated, the PET sheet was bonded to a treatment surface of a
CPP sheet (Torayfan No. ZK-99 manufactured by Toray Advanced Film
Co., Ltd., 60 microns), and then aged for four days at 60.degree.
C., to give a composite sheet. The composite sheet was subjected to
a peel test (201B type (with a constant temperature bath) precision
universal testing machine of INTESCO Co., Ltd. a testing sample
width 15 mm, a testing speed 50 mm/min) at 80.degree. C. to
determine the peel strength. The results are shown in Table 2.
[0091] In Table 2, under the "mode" in parenthesis, "cohesion"
indicates cohesion and peeling of the adhesive itself, suggesting
that cohesive strength of the adhesive is weaker than the adhesion
strength at the interface between the adhesive and the sheet. The
"cohesion" indicates insufficient adhesion strength even if the
peel strength is high.
2) Transparency and Degree of Yellowing
[0092] The laminating adhesives of Examples and Comparative
Examples were applied in an amount of about 5 g/m.sup.2 on the
surface of a glass plate (JIS R 3202 manufactured by Nippon
Testpanel Co., Ltd.), and the plate was bonded to an untreated
surface of a CPP sheet (NO ZK-99 manufactured by Toray Advanced
Film Co., Ltd 60 microns), and then aged for four days at
60.degree. C.
[0093] Thereafter, the CPP film was peeled off, and irradiated with
light using a QUV device for 50 hours continuously. After the plate
was taken from the device, transparency was observed, and evaluated
as transparency after 50 hours. At the same time, a b-value was
measured using a colorimeter. Further, light irradiation was
performed using the QUV device for 100 hours continuously. After
the plate was taken from the device, transparency was observed, and
evaluated as transparency after 100 hours. At the same time, a
b-value was measured using a colorimeter. Using the difference of
these b-values, i.e. Ab-value, the degree of yellowing of the cured
laminating adhesive was evaluated. The results are shown in Table
2. QUV device: Dewpanel Light Control Weather Meter FDP
(manufactured by Suga Test Instruments Co., Ltd.), continuous
irradiation, 70.degree. C., 10% RH, irradiance setting 28 W/m.sup.2
Colorimeter: spectroscopic colorimeter SE-2000 (manufactured by
Nippon Denshoku Industries Co., Ltd.), measurement method:
transmittance method
TABLE-US-00002 TABLE 2 Examples Mixing Ratio Cvclohexane and
Polyiso- (Weight Ratio) Ring Peel Strength Transparency Degree of
Comparative Polyol cyanate OH NCO Concentration at 80.degree. C.
(N) After After Yellowing Examples Component Component Component
Component (mmol/g) (Mode) 50 Hours 100 Hours .DELTA.B-Value Example
1 A A 16 1 1.073 2.6 a a 0.05 (Interface) Example 2 B A 16 1 0.591
2.1 a a -0.06 (Interface) Example 3 B B 9 2 1.032 2.2 a a 0.08
(Interface) Example 4 C A 20 1 0.307 2.3 a a 0.04 (Interface)
Example 5 D A 20 1 0.196 2.3 a a 0.05 (Interface) Example 6 E A 13
1 1.388 2.5 a a 0.04 (Interface) Example 7 F A 13 2 1.615 1.6 a a
0.08 (Interface) Example 8 F B 9 5 2.534 Sheet b b 0.03 Fracture
Example 9 F C 4 1 2.587 3.1 a a -0.02 (Surface Layer) Example 10 G
A 16 1 0.576 1.7 a a 0.06 (Interface) Example 11 H A 16 1 0.391 2.1
a a 0.09 (Interface) Example 12 I A 6 1 2.088 2.1 a a 0.17
(Interface) Example 13 J A 20 1 0.196 1.0 a a 0.06 (Interface)
Example 14 K A 17 1 0.284 4.8 a a -0.07 (Surface Layer) Example 15
L A 16 1 0.356 1.2 a a 0.04 (Interface) Example 16 M A 16 1 0.360
1.2 a a 0.06 (Interface) Example 17 A C 16 1 1.432 2.8 a a 0.04
(Interface) Comp. N A 20 1 0 4.7 c c -- * 1 Ex. 1 (Interface) Comp.
O A 15 1 0 3.4 a a 0.02 Ex. 2 (Cohesion) Comp. P A 9 1 0 1.2 c c --
* 1 Ex. 3 (Interface) Comp. Q A 20 1 0 4.6 a a 2.08 Ex. 4
(Cohesion) Transparency Evaluation * 1 Adhesive coating was not
transparent and not able to be evaluated a: Transparent b: Frost c:
Opaque
3) Heat-And-Humidity Resistance Test
[0094] The laminating adhesives of Examples 1, 2, and 17, and
Comparative Example 4 were applied in an amount of about 5
g/m.sup.2 on a treatment surface of a CPP sheet (NO ZK-99,
manufactured by Toray Advanced Film Co., Ltd., 60 microns), and
after the solvent was evaporated, the sheet was bonded to a
treatment surface of another CPP sheet, and then aged for four days
at 60.degree. C. to give a composite sheet. The composite sheet was
set in a Highly Accelerated Stress Test System (model number:
TPC-411, manufactured by TABAI ESPEC Corp.), and tested for 168
hours under conditions of 120.degree. C., 85% RH, and 1.6
atmospheric pressures. Thereafter, a peel test (201B type precision
universal testing machine of INTESCO Co. Ltd., testing sample width
15 mm, testing speed 300 mm/min) was performed at room temperature
to obtain a peel strength, and then a retention rate
(heat-and-humidity resistance test/peel strength retention rate
(%)) of peel strength after the test of 168 hours was obtained,
setting the peel strength before the test as 100%. The results are
shown in Table 3.
TABLE-US-00003 TABLE 3 Mixing Ratio Cyclohexane Heat-and-Humidity
Resistance Polyiso- (Weight Ratio) Ring Test/Peel Strength Examples
And Polyol cyanate OH NCO Concentration Retention Rate (%) Comp.
Examples Component Component component component (mmol/g) 168 hr
Example 1 A A 16 1 1.073 84 Example 2 B A 16 1 0.591 102 Example 17
A C 16 1 1.432 74 Comp. Example 4 Q A 20 1 0 43
[0095] While the illustrative embodiments of the present invention
are provided in the above description, such is for illustrative
purpose only and it is not to be construed as limiting the scope of
the present invention. Modification and variation of the present
invention that will be obvious to those skilled in the art is to be
covered by the following claims.
INDUSTRIAL APPLICABILITY
[0096] The laminating adhesive of the present invention is suitably
used for laminating outdoor composite sheets.
* * * * *