Note: Descriptions are shown in the official language in which they were submitted.
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W0429
57/6
Method for Preparing Modified Wooden Material
This invention relates to a method for preparing a
wooden material using an aqueous water repellent for the
1o treatment of a substrate. It also relates to an aqueous
water repellent useful for the treatment of substrates such
as paper, fibers, brick and materials originating from
lignocellulose such as wood for the purposes of preventing
paper from dimensional changes by water or ink and improving
print properties, or imparting water repellency to fibers
and materials originating from lignocellulose such as wood,
and a method for preparing the same. It. also relates to a
method for preparing a plywood or a laminated veneer lumber
and a method for preparing a wooden fiberboard.
In the prior art, many methods are known for imparting
dimensional stability and water repellency to substrates,
for example, paper items, fibrous items and building
materials such as wood and brick. Typically, materials are
coated or impregnated with solutions of silicone, acrylic,
urethane, ester, fatty and oily resins or monomers, followed
by drying. Of these repellents, silicone repellents are
wide spread. In particular, silicone water repellents of
the solvent dilution type become the main stream.
However, water repellents of the solvent dilution type
generally have a more negative influence of the solvent on
the environment than the water dilution type. Also from the
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standpoints of environmental protection and resource
preservation, there is a strong desire to have water
repellents which do not use solvents, especially aqueous
water repellents of high performance.
While many aqueous water repellents were recently
developed, JP-A 1-292089 (published November 24, 1989), JP-A 5-
156164 (published June 6, 1993) and JP-A 5-221748 (published
August 31, 1993) disclose long term stable emulsions having
alkyltrialkoxysilanes emulsified in water. However, these
emulsions have several drawbacks since they use
to alkoxysilanes characterized by very slow hydrolytic
reaction. When the emulsion is applied to a material, the
material is effectively impregnated therewith, but the
silane volatilizes off from the material surface. As a
result, the material surface loses water repellency, becomes
vulnerable to water wetting, staining and popup by frosting
and thus undesirably less durable, and looks milky white on
outer appearance.
Aside from the emulsion type mentioned above, JP-A
61-162553 (published July 23, 1986), JP-A 4-249588 (published
September 4, 1992) and JP-A 10-81752 (published March 31, 1998)
2o disclose water repellents of homogeneous aqueous solution type.
However, the composition of JP-A 61-162553 lacks
storage stability in that rapid polymerization reaction
takes place upon dilution with water. The composition must
be used within a day after dilution and is thus impractical.
The rapid polymerization reaction leads to a molecular
weight build-up, which retards impregnation of the material
therewith, sometimes leaving wet marks on the material
surface.
The composition of JP-A 4-249588 comprising a
3o water-soluble amino group-containing coupling agent and an
alkyltrialkoxysilane having a short carbon chain has good
storage stability, but poor water repellency probably
because only the lower alkyl group contributes to water
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repellency. Since the amino group-containing coupling agent
component is included in excess of the alkylalkoxysilane
component as demonstrated by a molar ratio of
alkylalkoxysilane component/amino group-containing coupling
agent in the range from 0.5/10 to 3/l, there are problems
that wet color marks are left on the material surface and
paper, fibrous items and wood are substantially yellowed.
JP-A 2000-95868 (published April 4, 2000) discloses a method
for preparing a composition by first partially hydrolyzing an
1o alkyltrialkoxysilane or alkyldialkoxysilane having a short
carbon chain and an amino group-containing alkoxysilane,
adding hydrolytic water and an acid to effect further
hydrolysis, and finally adding a neutralizing agent. This
method is complex. In the first step of effecting
hydrolytic reaction on a mixture of the alkylalkoxysilane
and the amino group-containing alkoxysilane, the amino
group-containing alkoxysilane generally has a higher
hydrolytic rate than the alkylalkoxysilane, which becomes a
bar against co-hydrolysis, failing to effectively form a
2o co-hydrolytic product. The composition finally obtained by
this method is thus unsatisfactory. Treatment of neutral
substrates with the composition undesirably imparts poor
water repellency.
JP-A 7-15031 (published April 20, 1994)
discloses the treatment of wood with a composition
comprising a salt of an organic or inorganic
acid with a basic nitrogen-containing organopolysiloxane, a
water repellent substance and water. This composition,
however, has the problems of insufficient water repellency
3o and storage instability.
JP-A 55-133466 (published October 17, 1980) and JP-A
55-133467 (published October 17, 1980) disclose a
composition obtained by hydrolyzing an alkylalkoxysilane, an
amino group-containing alkoxysilane, an epoxy group-
containing alkoxysilane and a metal-metalloid salt with
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water. The treatment of substrates with the composition
minimizes yellowing. However, since amino groups are
blocked by the reaction of amino groups with epoxy groups,
the composition becomes so difficultly soluble in water that
it cannot be used as an aqueous treating agent. The amino
blocking also restrains the adsorption of the composition to
substrates so that the composition cannot be used for the
treatment of substrates.
To solve the above problems, we proposed in JP-A
9-77780 (published March 25, 1997) a composition
comprising the co-hydrolyzate of an
alkylalkoxysilane having 7 to 18 carbon atoms, an alkoxy
group-containing siloxane and an amino group-containing
alkoxysilane. Despite the use of long chain alkyl silane,
the composition provides substrates with weak water
repellency. When paper, fibrous items and wood are treated
with the composition, somewhat noticeable yellowing occurs.
Proposed in JP-A 10-81752 is a binder composition
which is stable in an alkaline region. Due to a substantial
amount of amino group-containing alkoxysilane used therein,
2o this composition had many problems including insufficient
water repellency as an agent for treating non-alkaline
substrates, wet color left on the treated material, and
substantial yellowing.
Accordingly, all the water repellents described above
are seldom regarded as performing satisfactorily for the
treatment of substrates, especially neutral (weakly acidic
to weakly alkaline) substrates.
On the other hand, housing members available at
present include plywood members which are often used as
bearing wall members, structural floor sheathing members,
and roof sheathing members, and laminated veneer lumber
which are often used as two-by-four members and Japanese
traditional wooden framework members.
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It has heretofore been possible to produce plywood and
laminated veneer lumber from a useful wood raw material
having excellent properties which is selected for a
particular purpose or application from among wood raw
materials having relatively good properties, for example,
tropical timber. Due to the depletion of wood resources, it
is not always possible under the currently prevailing
circumstances to use only a wood raw material having
excellent properties. Now that the regulation of insuring
1o and promoting the quality of houses and buildings has been
enforced, the quality demand to housing members is and will
be increasing. It is forecasted that the future need is to
produce plywood or laminated veneer lumber which are less
expensive, have good physical properties and impose a less
load to the environment upon discarding.
These facts suggest that with the progress of
depletion of wood resources, the preparation of wooden
panels from a wood material having excellent properties as
the raw material is not always possible. In particular,
2o plywood and laminated veneer lumber products from a typical
forested tree, Radiate pine (Pinus Radiata D. DON) as the
raw material have not been widespread because of problems
including dimensional changes, warping and mildewing due to
their high water and moisture absorptive properties.
One conventional approach use to solve these problems
is to apply emulsions of acrylic water repellents or
paraffinic water repellents. However, a blocking problem
often occurs when these water repellents are applied to
plies and dried and the plies are piled up. This problem
precludes widespread use in practical applications.
For the preparation of wooden fiberboards, wet and dry
methods are known in the art. In either method,
sheet-shaped articles of wooden fibers obtained by paper
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machining or sheeting are generally heat compression molded
by means of a hot press or similar equipment. The heat
compression molded fiberboards, immediately after exiting
from the hot press, are cooled and piled up in a cooling
equipment of the elevator or wicket type.
In the method of preparing such fiberboards, it is
common to use adhesives comprising formaldehyde-containing
resins such as urea-formaldehyde resins, melamine-
formaldehyde resins, and phenol-formaldehyde resins, alone
or in admixture. At the same time, various waxes are used
in the adhesives to impart water resistance to the
fiberboards, for example, so-called synthetic waxes such as
acrylic waxes, polyethylene waxes synthesized from
polyethylene having a low degree of polymerization or acid
modified products thereof, Fischer-Tropsch wax synthesized
from carbon monoxide and hydrogen, and amide waxes
synthesized from various fatty acids and ammonia or amine;
petroleum base waxes such as paraffin wax and
microcrystalline wax, and mineral waxes such as montan wax,
ozokerite and ceresine.
Also, since the wooden fiberboards are molded under
pressure, they experience substantial dimensional changes
due to absorption and release of moisture or water after the
molding. When they were actually used in houses, problems
frequently occurred. Then studies have been made to improve
the water resistance of wooden fiberboards for the purpose
of improving the dimensional stability of wooden
fiberboards. Besides the above-mentioned exemplary solution
of wax addition, it has also been proposed to use isocyanate
base adhesives having high water resistance, to carry out
heat or steam treatment at high temperature (150 to 200°C),
and to carry out chemical treatment such as formalization.
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However, the use of the above-mentioned waxes as means
for improving the water resistance of wooden fiberboards
generally tends to compromise the strength performance of
fiberboards such as bending strength and internal bond
strength. The use of isocyanate base adhesives has been
under study and actual use as mentioned above, although
these adhesives are very expensive as compared with
urea-formaldehyde base resins and melamine-formaldehyde base
resins, and so toxic that meticulous handling and strict
1o management are required on their use as well as the new
addition or modification of a safety security step.
Among the water resistance-ameliorating measures, the
use of isocyanate base adhesives having high water
resistance has the problems of expensiveness and meticulous
handling and strict management on their use as described
just above; and the heat treatment at high temperature (150
to 200°C) has the drawback of an increased cost required to
provide the high temperature and further raises the problem
of requiring an extra step of increasing the water content
of fiberboards, which has been once decreased to nearly
absolute dryness during the treatment, to a water content (5
to 130) which is acceptable on practical use. The steam
treatment has the problems that the processing equipment is.
costly, and the running cost is very high. The chemical
treatment such as formalization is very costly in itself and
in the case of formalization, the increased amount of
formaldehyde released is a problem.
Further, a method involving applying a surface
modifier to a sheet-shaped member of wood fibers as by
spraying, followed by heat compression molding, as disclosed
in JP-A 2001-260104, (published September 25, 2001),
has the problem that since excessive portions are
cut away in finishing the member into a
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r
product, water can penetrate into the member through end
faces so that member is readily swollen.
As discussed above, the prior art methods of improving
water resistance have problems on practical usage in that
reagents such as waxes are cost effective, but induce a
decline of the strength performance of wooden fiberboards,
the above-described adhesives, heat treatment, steam
treatment and chemical treatment are effective for improving
water resistance, but invite cost increases that is, any of
these measures fails to satisfy both of these requirements.
An object of the invention, which has been made in
consideration of the above-mentioned circumstances, is to
provide an aqueous water repellent for the treatment of
substrates of materials originating from lignocellulose or
the like which is improved in impregnation of the substrates
therewith and imparts dimensional stability and water
repellency to the treated substrates, and a method for
preparing the same.
Another object of the invention is to provide a method
for preparing a modified wooden material using an aqueous
water repellent for the treatment of substrates as mentioned
above.
A further object of the invention is to provide a
method for preparing modified plywood or modified laminated
veneer lumber, which method can render plywood or laminated
veneer lumber termite-proof, rot-proof, mildew-proof, water
resistant, moisture resistant and dimensional stable and
thus accomplish the desired performance without detracting
from the lightweight advantage thereof.
A further object of the invention is to provide a
method for preparing wooden fiberboards, in which wooden
fiberboards endowed with water resistance, durability and
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r a
strength performance can produced at a high productivity and
low cost.
Making extensive efforts to accomplish the above
objects, the inventors have discovered that when a product
is obtained by effecting co-hydrolytic condensation in the
presence of an organic acid or inorganic acid of
(A) 100 parts by weight of an organosilicon compound
to having the following general formula (1):
(R1) a (0R2) bSiO~Q_a_b~/2 ( 1)
wherein R1 is an alkyl group having 1 to 6 carbon atoms, R2
is an alkyl group having 1 to 4 carbon atoms, letter a is a
positive number of 0.75 to 1.5, b is a positive number of
0.2 to 3 and a+b is from more than 0.9 to 4, and
(B) 0.5 to 49 parts by weight of an amino
group-containing alkoxysilane having the following general
2o formula (2)
R3R9NR5-SlR6n ( ORZ ) 3_n ( 2 )
wherein RZ is as defined above, R3 and R4 each are
independently hydrogen or an alkyl or aminoalkyl group
having 1 to 15 carbon atoms, RS is a divalent hydrocarbon
group having 1 to 18 carbon atoms, R6 is an alkyl group
having 1 to 4 carbon atoms, and n is 0 or 1, or a partial
hydrolyzate thereof, and especially the organosilicon
compound is made alcohol-free by removing an alcohol from
the reaction system, surprisingly, the co-hydrolytic
condensation product itself is soluble in water and remains
uniform upon dissolution in water, can be used simply after
dilution with water, and maintains good storage stability
even after water dilution, although the amount of the amino
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f
group-containing alkoxysilane component is small relative to
the short chain alkyltrialkoxysilane or alkoxy
group-containing siloxane. The co-hydrolytic condensation
product is effective in penetrating into substrates for
thereby imparting durable water repellency and dimensional
stability to the substrates. When organic materials such as
paper, fibrous items and wood are treated with the
co-hydrolytic condensation product, yellowing is minimized
due to the reduced content of the amino group-containing
l0 alkoxysilane component. Since the long chain alkylsilane
component which was necessary in the prior art to impart
water repellency is eliminated, the cost of the silane
component is reduced, leading to an economic advantage. In
summary, the co-hydrolytic condensation product is improved
in impregnation of substrates therewith, effective for
imparting dimensional stability, water repellency and
durable water repellency to the substrates, and available at
a low cost.
Thus, the inventors have discovered that a wooden
2o material is quite effectively modified by the treatment with
the product as mentioned above.
Also, making extensive investigations to develop a
method for preparing improved plywood or laminated veneer
lumber from a wood raw material not fully satisfying the
required properties, the inventors have also discovered a
method for preparing a modified wooden panel having improved
termite-proof, rot-proof, mildew-proof properties, water
resistance, moisture resistance and dimensional stability,
by impregnating plywood or laminated veneer lumber with the
3o above-described aqueous water repellent over regions
extending from its front and back surfaces to a first
adhesive layer, that is, typically from its front and back
surfaces to a depth of 0.5 to 10 mm in a face and back
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veneer thickness direction, and effecting hydrolytic
polycondensation for creating and securing to inner surfaces
of inter- and intracellular spaces in wood an
inorganic-organic composite substance based on silicon oxide
(Si02) giving a minimal load to the environment upon
discarding. The inventors have also discovered a method for
preparing more excellent modified plywood or modified
laminated veneer lumber by simultaneously applying the same
reagent to a cut section or machined section of plywood or
l0 laminated veneer lumber as well.
Furthermore, the inventors have discovered that by
adding the above-described aqueous water repellent to wooden
fibers and heat compression molding them, a wooden
fiberboard is improved in both water resistance and strength
performance. The present invention is predicated on these
discoveries.
Accordingly, in a first aspect, the invention provides
an aqueous water repellent for the treatment of a substrate,
comprising the product of co-hydrolytic condensation of
(A) 100 parts by weight of an organosilicon compound
having the following general formula (1):
( R1 ) a ( ~RZ ) bSl~ (9_a_b) /2 ( 1 )
wherein R1 is an alkyl group having 1 to 6 carbon atoms, R2
is an alkyl group having 1 to 4 carbon atoms, letter a is a
positive number of 0.75 to 1.5, b is a positive number of
0.2 to 3 and a+b is from more than 0.9 to 4, and
(B) 0.5 to 49 parts by weight of an amino
group-containing alkoxysilane having the following general
formula (2):
R3R9NR5-SlR6n ( ORZ ) 3_n ( 2 )
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r
wherein R2 is as defined above, R3 and R9 each are
independently hydrogen or an alkyl or aminoalkyl group
having 1 to 15 carbon atoms, RS is a divalent hydrocarbon
group having 1 to 18 carbon atoms, R6 is an alkyl group
having 1 to 4 carbon atoms, and n is 0 or l, or a partial
hydrolyzate thereof, the co-hydrolytic condensation being
effected in the presence of an organic acid or inorganic
acid; and a method for preparing an aqueous water repellent
for the treatment of a substrate, comprising effecting
to co-hydrolytic condensation of the above-defined components
(A) and (B) in the above-specified amounts in the presence
of an organic acid or inorganic acid. In this embodiment,
an aliphatic quaternary ammonium compound and/or a
boron-containing compound is preferably added to the water
repellent.
In another aspect, the invention provides a method for
preparing a modified wooden material using an aqueous water
repellent for the treatment of a substrate as mentioned
above.
2o In a further aspect, the invention provides a method
for preparing a modified plywood or a modified laminated
veneer lumber, comprising the step of impregnating a plywood
or a laminated veneer lumber with the aqueous water
repellent from its front and back surfaces, for causing the
water repellent to selectively penetrate into wood inter-
and intracellular spaces in regions of the plywood or the
laminated veneer lumber between the front and back surfaces
and first adhesive layers disposed closest to the front and
back surfaces. In this embodiment, the plywood or the
laminated veneer lumber has a cut or machined section, and
the same water repellent as used herein is preferably
applied to the cut or machined section of the plywood or the
laminated veneer lumber for impregnation.
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In a further aspect, the invention provides a method
for preparing a wooden fiberboard, comprising the step of
heat compression molding a sheet-shaped member of wooden
fibers having the aqueous water repellent added thereto,
using an adhesive; and a method for preparing a wooden
fiberboard, comprising the step of heat compression molding
a sheet-shaped member of wood fibers, using an adhesive
having the aqueous water repellent added thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a plywood or a
laminated veneer lumber impregnated from its front and back
surfaces with an aqueous water repellent according to the
invention.
FIG. 2 is a cross-sectional view of a plywood or a
laminated veneer lumber having applied to its cut or
machined sections an aqueous water repellent according to
the invention. FIG. 2A illustrating application of the
water repellent to end surfaces; FIG. 2B illustrating
2o impregnation with the water repellent from end surfaces;
FIG. 2C illustrating application of the water repellent to
machined surfaces FIG. 2D illustrating impregnation with
the water repellent from end surfaces.
FIG. 3 is a graph showing changes with time of percent
water absorption of Example 8 and Comparative Example 6 in
Test 1.
FIG. 4 is a graph showing changes with time of percent
thickness swelling of Example 8 and Comparative Example 6 in
Test 1.
3o FIG. 5 is a graph showing changes with time of percent
width swelling of Example 8 and Comparative Example 6 in
Test 1.
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FIG. 6 is a graph showing changes with time of percent
water absorption of Example 8 and Comparative Example 6 in
Test 2.
FIG. 7 is a graph showing changes with time of percent
thickness swelling of Example 8 and Comparative Example 6 in
Test 2.
FIG. 8 is a graph showing changes with time of percent
width swelling of Example 8 and Comparative Example 6 in
Test 2.
1o FIG. 9 is a graph showing changes with time of percent
water absorption of Example 9 and Comparative Example 7.
BEST MODE FOR CARRYING OUT THE INVENTION
Now the present invention is described in more detail.
Component (A) used to produce the aqueous water
repellent for the treatment of substrates according to the
invention is an organosilicon compound having the following
general formula (1).
( R1 ) a ( ORz ) bCJlO (q_a_b) /2 ( 1 )
Herein R1 is an alkyl group having 1 to 6 carbon atoms, R2 is
an alkyl group having 1 to 4 carbon atoms, letter a is a
positive number of 0.75 to 1.5, b is a positive number of
0.2 to 3 and a+b is from more than 0.9 to 4.
More particularly, in formula (1), R1 is an alkyl
group having 1 to 6 carbon atoms, preferably 1 to 3 carbon
atoms. Examples include methyl, ethyl, n-propyl, isopropyl,
n-butyl, isobutyl, n-pentyl and n-hexyl, with methyl being
3o preferred.
R2 is an alkyl group having 1 to 4 carbon atoms, for
example, methyl, ethyl, n-propyl, isopropyl, n-butyl and
isobutyl, with methyl and ethyl being preferred.
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Illustrative examples of the organosilicon compound of
formula (1) are given below.
CH3Si (OCH3) 3, CH3Si (OC2H5) 3~
CH3S 1 ( OCH ( CH3 ) 2 ) 3, CH3CH2Si ( OCH3 ) 3,
CH3CHZSi ( OCZHS ) 3, CH3CH2Si ( OCH ( CH3 ) 2 ) 3,
C3H6S1 ( OCH3 ) 3, C3H6S1 ( OCZHS ) 3
C3H6Si (OCH (CH3) 2) 3~ C9H9S1 (OCH3) 3~
C4H9S1 ( OCZHS ) 3, C9H9Si ( OCH ( CH3 ) 2 ) 3,
CSHIISi ( OCH3 ) 3, CsHiiSi ( OC2H5 ) 3 r
CSHIISi ( OCH ( CH3 ) 2 ) 3, C6H13Si ( OCH3 ) 3,
C6H13Si ( OC2H5 ) 3, CsHl3Si ( OCH ( CH3 ) 2 ) s
These silanes may be used alone or in admixture of
any. Partial hydrolyzates of mixed silanes are also useful.
Herein, alkoxy group-containing siloxanes resulting
i5 from partial hydrolytic condensation of the above silanes
are preferably used as component (A). The partial
hydrolyzates (siloxane oligomers) preferably have 2 to 10
silicon atoms, especially 2 to 4 silicon atoms. The
reaction products of alkyltrichlorosilanes having 1 to 6
carbon atoms with methanol or ethanol in water may also be
used as component (A). In this case too, the siloxane
oligomers preferably have 2 to 6 silicon atoms, especially 2
to 4 silicon atoms. Of these siloxane oligomers, siloxane
dimers of the formula [CH3(ORZ)ZSi]20 are especially
preferred. They may contain siloxane trimers and siloxane
tetramers. The preferred siloxane oligomers are those
having a viscosity of up to 300 mm2/s at 25°C, especially 1
to 100 mm2/s at 25°C.
Component (B) is an amino group-containing
alkoxysilane having the following general formula (2) or a
partial hydrolyzate thereof.
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R3R4NR5-SlR6n ( ORz ) 3_n ( 2 )
Herein Rz is as defined above, R3 and R', which may be the
same or different, are independently hydrogen or an alkyl or
aminoalkyl group having 1 to 15 carbon atoms, preferably 1
to 8 carbon atoms, more preferably 1 to 4 carbon atoms, RS
is a divalent hydrocarbon group having 1 to 18 carbon atoms,
preferably 1 to 8 carbon atoms, more preferably 3 carbon
atoms, R6 is an alkyl group having 1 to 4 carbon atoms, and
1o n is 0 or 1.
In formula (2), examples of R3 and R9 include methyl,
ethyl, propyl, butyl, aminomethyl, aminoethyl, aminopropyl
and aminobutyl. Examples of RS include alkylene groups such
as methylene, ethylene, propylene and butylene. Exemplary
of R6 are methyl, ethyl, propyl and butyl.
Illustrative examples of the amino group-containing
alkoxysilane of formula (2) are given below.
HZN ( CHz ) zSi. ( OCH3 ) 3, H2N ( CHz ) zSi ( OCH2CH3 ) 3,
H2N ( CHz ) 3Si ( OCH3 ) 3, H2N ( CHz ) 3Si ( OCH2CH3 ) 3,
CH3NH ( CHz ) 3Si ( OCH3 ) 3, CH3NH ( CHz ) 3Si ( OCH2CH3 ) 3,
CH3NH ( CHz ) 5Si ( OCH3 ) 3, CH3NH ( CHz ) SSi ( OCHZCH3 ) 3,
HZN ( CHz ) zNH ( CHz ) 3Si ( OCH3 ) 3,
HZN ( CHz ) zNH ( CHz ) 3S i ( OCHZCH3 ) 3
CH3NH ( CHz ) zNH ( CHz ) 3Si ( OCH3 ) 3,
CH3NH ( CHz ) zNH ( CHz ) 3Si ( OCHzCH3 ) 3 ~
C9H9NH ( CHz ) zNH ( CHz ) 3S i ( OCH3 ) 3,
C9H9NH ( CHz ) zNH ( CHz ) 3S i ( OCH2CH3 ) 3 ~
H2N (CHz) zSiCH3 (OCH3) z,
HZN ( CHz ) zSiCH3 ( OCHZCH3 ) z,
HZN ( CHz ) 3SiCH3 ( OCH3 ) z,
H2N ( CHz ) 3SiCH3 ( OCHZCH3 ) z,
CH3NH ( CHz ) 3SiCH3 ( OCH3 ) z,
CH3NH ( CHz ) 3SiCH3 ( OCHZCH3 ) z.
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CH3NH ( CHz ) SSiCH3 ( OCH3 ) z,
CH3NH ( CHz ) SSiCH3 ( OCHzCH3 ) z,
H2N ( CHz ) zNH ( CHz ) 3Si.CH3 ( OCH3 ) z,
H2N ( CHz ) zNH ( CHz ) 3SiCH3 ( OCH2CH3 ) z,
CH3NH ( CHz ) zNH ( CHz ) 3SiCH3 ( OCH3 ) z,
CH3NH ( CHz ) zNH ( CHz ) 3SiCH3 ( OCHZCH3 ) z,
C9H9NH ( CHz ) zNH ( CHz ) 3SiCH3 ( OCH3 ) z,
C9H9NH ( CHz ) zNH ( CHz ) 3SiCH3 ( OCH2CH3 ) z
Of these, preferred are N-(2-aminoethyl)-3-amino-
1o propyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyl-
methyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltri-
ethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxy-
silane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyl-
dimethoxysilane, 3-aminopropyltriethoxysilane, and
3-aminopropylmethyldiethoxysilane.
With respect to the mixing proportion of components
(A) and (B), 0.5 to 49 parts, preferably 5 to 30 parts by
weight of component (B) is used per 100 parts by weight of
component (A) (all parts being by weight, hereinafter).
2o With less than 0.5 part of component (B), the product
becomes less water soluble and unstable in aqueous solution
form. The product using more than 49 parts of component (B)
may become poor in water repellency and long-term inhibition
of water absorption and cause considerable yellowing when
substrates are treated therewith.
Stated on a molar basis, components (A) and (B) are
used such that 0.01 to 0.3 mol, especially 0.05 to 0.2 mol
of Si atoms in component (B) are available per mol of Si
atoms in component (A).
3o In preparing the aqueous water repellent using
components (A) and (B), co-hydrolysis is carried out on
components (A) and (B) in the presence of an organic acid or
inorganic acid.
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CA 02392656 2002-07-05
In a preferred embodiment, the co-hydrolytic
condensation product is obtained by first hydrolyzing
component (A) in the presence of an organic acid or
inorganic acid, mixing the resulting hydrolyzate with
component (B), and effecting further hydrolysis in the
presence of an organic acid or inorganic acid.
The organic acid or inorganic acid used for the first
hydrolysis of component (A) is at least one acid selected
from among hydrochloric acid, sulfuric acid, methanesulfonic
1o acid, formic acid, acetic acid, propionic acid, citric acid,
oxalic acid and malefic acid. Of these, acetic acid and
propionic acid are preferred. The acid is preferably used
in an amount of 2 to 40 parts, more preferably 3 to 15 parts
per 100 parts of component (A).
Hydrolysis is preferably carried out in a state
diluted moderately with a solvent. The solvent is
preferably selected from alcoholic solvents, especially
methanol, ethanol, isopropyl alcohol and tert-butyl alcohol.
An appropriate amount of the solvent used is 50 to 300
2o parts, more preferably 70 to 200 parts per 100 parts of
component (A). With less than 50 parts of the solvent,
excessive condensation may take place. With more than 300
parts of the solvent, hydrolysis may take a longer time.
The amount of water added to component (A) for
hydrolysis is preferably 0.5 to 4 mol, especially 1 to 3 mol
per mol of component (A). If the amount of water added is
less than 0.5 mol, there may be left more alkoxy groups.
With more than 4 mol of water, excessive condensation may
take place. Preferred reaction conditions for hydrolysis of
component (A) include a reaction temperature of 10 to 40°C,
especially 20 to 30°C and a reaction time of 1 to 3 hours.
The hydrolyzate of component (A) thus obtained is then
reacted with component (B). Preferred reaction conditions
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CA 02392656 2002-07-05
of this step include a reaction temperature of 60 to 100°C
and a reaction time of 1 to 3 hours. At the end of
reaction, the reaction system is heated above the boiling
point of the solvent for distilling off the alcohol solvent.
Preferably the alcohol solvent is distilled off until the
content of entire alcohols (including the alcohol as
reaction medium and the alcohol as by-product) in the system
becomes 30% by weight or less, especially 10% by weight or
less. If the product contains much alcohol, it may become
l0 white turbid or gel when diluted with water, and lose
storage stability. The reaction product obtained by the
above-described method should preferably have a viscosity of
5 to 2,000 mm2/s at 25°C, especially 50 to 500 mm2/s at 25°C.
Too high a viscosity may adversely affect ease of working
and storage stability and reduce the solubility in water.
The product preferably has a weight average molecular weight
in the range of 500 to 5,000, especially 800 to 2,000.
The aqueous water repellent of the invention is
comprised of the co-hydrolytic condensation reaction product
of components (A) and (B) obtained by the above-described
method. Presumably because the product is present dissolved
or in micelle state in an aqueous solution due to compliant
orientation of hydrophilic moieties (amino and silanol
groups) and hydrophobic moieties (alkylsilyl groups), the
product develops water solubility despite the low content of
component (B). The product exhibits good water repellency
regardless of the long chain alkylsilane component being
eliminated, good penetrability, and durable water repellency
presumably because of orientation with respect to the
3o substrate. When the repellent is applied to building
materials such as brick, minimal volatilization on the
surface prevents the surface from water wetting, staining
and popup by frosting. When the repellent is diluted with
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CA 02392656 2002-07-05
water, polymerization reaction in water is restrained, and
storage stability is improved.
In a preferred embodiment, (C) an aliphatic quaternary
ammonium compound and/or (D) a boron-containing compound is
added to the aqueous water repellent according to the
invention.
Preferably the aliphatic quaternary ammonium compound
(C) is a quaternary amino group-containing alkoxysilane
having the following general formula (3) or a partial
1o hydrolyzate thereof.
[ ( CH3 ) 2R7N ( CH2 ) 3-SlR6n ( OR2 ) 3-n] +X ( 3 )
Herein R2 and R6 are as defined above, R7 is a monovalent
hydrocarbon group having 11 to 22 carbon atoms, especially
alkyl or alkenyl, and n is 0 or 1. This is a component that
imparts antibacterial and antifungal properties to wood when
wood is treated with the aqueous water repellent.
In formula (3) , exemplary of R7 are -C11Hz3, -C12H25~
2~ -C16H31~ C16H33i C18H37i C20H91i and -C22H95 groups .
Illustrative and preferred examples of the quaternary
amino group-containing alkoxysilane having formula (3)
include
[ C12H2s ( CH3 ) 2N ( CH2 ) 3Si ( OCH3 ) 3 ] +C1 ,
[C14H29 (CH3) 2N (CH2) 3Si (OCH2CH3) 3] +C1-,
[ C16H33 ( CH3 ) 2N ( CH2 ) 3S1 ( OCH3 ) 3 ] +C1 ,
[ C16H33 ( CH3 ) 2N ( CH2 ) 3S i ( OCH2CH3 ) 3 ] +C1-,
[ C16H33 ( CH3 ) 2N ( CH2 ) 3SiCH3 ( OCH3 ) 2 ] +C1-,
[ C16H33 ( CH3 ) 2N ( CH2 ) 3S iCH3 ( OCH2CH3 ) 3 ] +C1-,
[ C1BH37 ( CH3 ) 2N ( CH2 ) 3Si ( OCH3 ) 3 ] +C1-,
[ C1eH37 ( CH3 ) 2N ( CH2 ) 3Si ( OCH2CH3 ) 3 ] +C1-,
[ C18H37 ( CH3 ) 2N ( CH2 ) 3SiCH3 ( OCH3 ) 2 ] +C1-, and
[ C1eH37 ( CH3 ) 2N ( CH2 ) 3S iCH3 ( OCH2CH3 ) 3 ] +C1- .
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CA 02392656 2002-07-05
The addition of component (C) can impart antibacterial
and antifungal properties. The amount of component (C)
blended is preferably 0.05 to 10 parts, especially 0.1 to 5
parts by weight per 100 parts by weight of aqueous water
repellent solids (co-hydrolytic condensate of components (A)
and (B)). Too small amounts may impart insufficient
antibacterial and antifungal properties whereas too large
amounts may adversely affect the storage stability of the
aqueous water repellent.
1o On the other hand, the boron-containing compound is
preferably a boric acid compound. Examples include
orthoborates such as InB03 and Mgj(B03)Z~ diborates such as
Mg2B205 and Co2B205; metaborates such as NaB02, KBO2, LiB02 and
Ca (B02) Z~ tetraborates such as Na2B407: and pentaborates such
as KB50g. Boric acids such as orthoboric acid (H3B03) ,
metaboric acid (HBOZ) and tetraboric acid (HZB907) are also
useful as well as borax (Na2B907 ~ 10H20) .
The addition of component (D) can impart termite-proof
property. The amount of component (D) blended is preferably
0.1 to 10 parts, especially 2 to 8 parts by weight per 100
parts by weight of aqueous water repellent solids
(co-hydrolytic condensate of components (A) and (B)). Too
small amounts may impart insufficient termite-proof property
whereas too large amounts may adversely affect the storage
stability of the aqueous water repellent.
The aqueous water repellent of the invention is used
in the treatment of substrates, especially paper, fibers,
brick, and lignocellulose-originating substances such as
wood for imparting water repellency. The lignocellulose-
originating substances include wooden materials such as
wood, plywood, laminated veneer lumber, wood particle
moldings and wooden fiberboards as well as paper and fibers
originating from cellulose.
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CA 02392656 2002-07-05
Specifically, the aqueous water repellent of the
invention is applicable to sheets of paper as a dimensional
stabilizer. The repellent not only prevents the paper from
being dimensional changes as by waving or cockling with
aqueous ink (as often used in ink jet printing), but also
improves the ink receptivity of the paper, offering good
printed image quality. The repellent is also applicable to
other substrates including various fibrous items and
building materials such as brick, wood, plywood, laminated
1o veneer lumber, and wooden fibers for fiberboards. The
repellent is a useful primer for various paints and finishes
as well.
When the above-mentioned substrates are treated with
the aqueous water repellent of the invention, the repellent
may be diluted with water to a concentration of 0.5 to 50%,
preferably 1 to 10% by weight, prior to use. With thin
dilution below 0.5% by weight, the repellent may fail to
exert its performance to a full extent and must be applied
in a larger amount, which may require a longer time for
2o drying. A concentration of more than 50% by weight
indicates insufficient dilution and gives too high a
viscosity to impregnate substrates therewith, sometimes
leaving coating marks and causing discoloration.
When the aqueous water repellent of the invention is
diluted with water to form an aqueous solution, the aqueous
solution should preferably be at pH 7 to 3, especially pH 6
to 4. If the aqueous solution is above pH 7 or alkaline,
the solution can damage cellulosic substrates such as paper
and wood. If the aqueous solution is below pH 3 or strongly
3o acidic, there arise problems that substrates are damaged and
equipment used for treatment are corroded. When synthesis
is carried out by the above-described method, there results
a co-hydrolytic condensation product falling in the above pH
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CA 02392656 2002-07-05
range. An aqueous repellent solution on a neutral to weakly
acidic level is best suited when substrates are treated
therewith.
Upon dilution of the aqueous water repellent of the
invention with water, various subordinate additives may be
added. Such additives include preservatives, antifungal
agents, termite controlling agents, flavors, colorants,
carboxymethyl cellulose, polyvinyl alcohol (PVA),
water-soluble acrylic resins, SBR latex, and colloidal
1o silica. Such optional component may be added in a
conventional amount as long as it does not compromise the
benefits of the invention.
When it is desired to cause the aqueous water
repellent to penetrate deeply into the substrate, a
surfactant may be added to the repellent to enhance its
penetrability.
The surfactant used herein is not critical and any of
well-known nonionic, cationic and anionic surfactants is
useful. Examples include nonionic surfactants such as
polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl
ethers, polyoxyethylene carboxylate, sorbitan fatty acid
esters, polyoxyethylene sorbitan fatty acid esters, and
polyether-modified silicones; cationic surfactants such as
alkyltrimethylammonium chloride and alkylbenzylammonium
chloride; anionic surfactants such as alkyl or alkylallyl
sulfates, alkyl or alkylallyl sulfonates, and dialkyl
sulfosuccinates; and ampholytic surfactants such as amino
acid and betaine type surfactants. Of these,
polyether-modified silicone surfactants are preferred.
An appropriate amount of the surfactant added is 0.01
to 5o by weight, more preferably 0.2 to 2.5% by weight based
on the solids of the aqueous water repellent. With less
than 0.01 by weight of the surfactant, the results are
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CA 02392656 2002-07-05
substantially unchanged from the results of treatment with
the aqueous water repellent alone, that is, substantially no
addition effect is achieved. More than 5% by weight of the
surfactant may sometimes adversely affect water absorption
inhibition and water repellency.
Rather than previously adding the surfactant to the
aqueous water repellent, a substrate may be pretreated with
a dilution of the surfactant prior to the treatment with the
aqueous water repellent. In this case, the surfactant is
1o diluted with water or an organic solvent to a concentration
of 0.01 to 5%, especially 0.1 to 2s by weight, the substrate
is pretreated with this surfactant dilution by roller
coating, brush coating or spraying or even by dipping, and
the substrate is then treated with the aqueous water
repellent: This procedure ensures that the repellent
penetrates deeply into the substrate.
In applying a water dilution of the aqueous water
repellent to the substrate, a roller, brush, spray or the
like may be used. In some cases, dipping may be used.
2o Application may be done under atmospheric pressure or
reduced pressure. The subsequent drying step may be holding
at room temperature, drying in the sun, or heat drying.
The aqueous water repellent with which the substrate
is impregnated in the above-described manner undergoes
hydrolytic reaction and condensation reaction to form a
tenacious water repellent layer. Therefore, when the
repellent is applied to a wooden material, the material is
improved in dimensional stability and become fully water
repellent, and further the problems of rot and mold caused
3o by water are eliminated. When the repellent is applied to
paper, the paper is improved in dimensional stability. When
the repellent is applied to fibrous items, the fibrous items
become fully water repellent. When the repellent is applied
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CA 02392656 2002-07-05
to building materials such as brick and wood, the problems
of blister, corrosion and mildewing caused by water are
eliminated. Additionally, the repellent serves as an
underlying water-proof primer for various paints and
finishes.
The aqueous water repellent of the invention is
advantageously used in the preparation of modified wooden
materials such as modified plywood and modified laminated
veneer lumber. Specifically, a plywood or a laminated
veneer lumber is impregnated and treated from its front and
back surfaces with the aqueous water repellent whereby the
regions of the plywood or the laminated veneer lumber
extending from the front and back surfaces to the first
adhesive layers (usually 0.5 to 10 mm in a thickness
direction) are selectively impregnated by utilizing the fact
that planar adhesive layers characteristic of the plywood
and the laminated veneer lumber prevent the solution from
easily penetrating beyond the adhesive layers when the
solution is applied to the front and back surfaces. In this
2o way, the desired performance is obtained while reducing the
amount of repellent impregnated per product volume. In the
process, the same solution is preferably applied to cut
sections and/or machined sections of the plywood or the
laminated veneer lumber for impregnation as well.
More particularly, the tree species of wooden raw
material from which the plywood or the laminated veneer
lumber is made is not critical, and the type of adhesive
resin used in the preparation of plywood and/or laminated
veneer lumber is not critical.
3o When the aqueous water repellent is applied to front
and back surfaces and cut sections or machined sections of
plywood or laminated veneer lumber for impregnation, the
temperature of plywood or laminated veneer lumber may be
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CA 02392656 2002-07-05
room temperature. However, it is desired that a temperature
on the order of 40 to 80°C be maintained not only on the
surfaces, but also in the interior of plywood or laminated
veneer lumber in order to ensure penetration. Inversely,
the aqueous water repellent heated at a temperature of 40 to
80°C may be used while keeping the plywood or the laminated
veneer lumber at room temperature. Since the water content
of plywood or laminated veneer lumber must fall in the range
clearing a level of up to 14% as prescribed by the Japanese
Agricultural and Forestry Standards, the aqueous water
repellent is applied in such amounts as to provide a water
content within that range.
It is noted that when the aqueous water repellent is
applied to both front and back surfaces of plywood and/or
laminated veneer lumber in a manufacturing line, with the
amount of evaporation by heat taken into account, the
preferable process involves the step of previously admixing
10 to 100 parts of water per 1 part of the co-hydrolytic
condensate of components (A) and (B) in the coating solution
or the step of applying water to both front and back
surfaces of plywood or laminated veneer lumber immediately
before the application of the aqueous water repellent. In
the latter case, the amount of water applied may be adjusted
so that 10 to 100 parts of water is available per 1 part of
the co-hydrolytic condensate of components (A) and (B).
Next, the coating weight and coating technique are
described. In the case of front surface coating, the
coating weight is such that 0.1 to 20 g, preferably 1 to 5 g
of the co-hydrolytic condensate of components (A) and (B) is
coated and impregnated per square meter surface area and per
millimeter of the distance from the front surface to the
first adhesive layer. The same applies in the case of back
surface coating. In the case of coating on a cut or
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CA 02392656 2002-07-05
machined section, the coating weight is such that 0.1 to 20
g, preferably 1 to 5 g of the co-hydrolytic condensate of
components (A) and (B) is coated and impregnated per square
meter cross-sectional area and per millimeter over a
distance of 1 to 5 mm from the sectional surface.
With respect to the coating technique, coating by
means of a roll coater or sponge roll is desired in a sense
of managing the coating weight while spray coating and
coating by vat immersion are also acceptable. To increase
to the immersion amount, the coating step may be repeated two
or more times.
FIG. 1 illustrates front and back impregnated regions
of a plywood or a laminated veneer lumber. A laminated
veneer lumber designated at 1 includes a plurality of
veneers 2 laminated via adhesive layers 3. A coating
apparatus such as a roll coater is designated at 4. By the
coating apparatus 4, the aqueous water repellent is
selectively applied to front and back veneers 2a and 2b for
impregnation to form impregnated layers 5.
2o FIG. 2 illustrates water repellent-impregnated regions
at end faces or machined sections of a plywood or a
laminated veneer lumber. The aqueous water repellent is
coated to end faces 6 or machined sections 7 by coating
means 8 such as sprays as shown in FIGS. 2A and 2C, thereby
forming impregnated regions 9 as shown in FIGS. 2B and 2D.
Referring to aging for gelation, the aqueous water
repellent of the invention generally requires 12 to 200
hours for aging for gelation after coating. Aging is
desirably conducted at an air temperature of 10 to 35°C in
3o fully ventilated conditions.
The preparation method described above ensures that
the plywood or the laminated veneer lumber which is
termite-proof, rot-proof, mildew-proof, water resistant,
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CA 02392656 2002-07-05
moisture resistant and dimensional stable so that it may be
used as main structural members or building interior members
be easily prepared without detracting from the texture
inherent to wood and without incurring blocking due to
deposition.
Furthermore, the aqueous water repellent of the
invention is advantageously used in the preparation of
wooden fiberboards. In one embodiment, the method for the
preparation of a wooden fiberboard involves adding the water
repellent to wooden fibers, then adding an adhesive, and
then heat compression molding a sheet-shaped member. The
amount of the water repellent added in this embodiment is
preferably 0.04 to 10 g per 100 g of the oven-dry wooden
fiber weight. Alternatively, a wooden fiberboard can be
prepared by heat compression molding a sheet-shaped member
of wooden fibers while using an adhesive having the water
repellent added thereto. The amount of the water repellent
added in the alternative embodiment is preferably 0.04 to 30
g per 100 g of the oven-dry wooden fiber weight.
2o More particularly, the method for the preparation of a
wooden fiberboard involves heat compression molding a
sheet-shaped member of wooden fibers. The sheet-shaped
member of wooden fibers is formed by fibrillating wood into
fibers or filaments, and paper-machining them into a sheet
or plate-shaped member by a wet or dry process.
Fibrillation may be carried out by various prior art
well-known techniques such as use of a grinder, use of a
disk refiner or attrition mill, and explosion. The
subsequent step of applying the aqueous water repellent to
3o wooden fibers may be conducted by applying within each of
the fibrillating machines or after exiting from each of the
fibrillating machines. The applying technique may use a
sprayer or dropping apparatus if feasible for a certain
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CA 02392656 2002-07-05
fibrillating machine. Alternatively, a necessary amount of
the aqueous water repellent may be added to the adhesive to
be admitted, prior to heat compression molding. It is noted
that the paper-machining technique may be either a wet
felting or air felting technique.
The heat compression molding step is the step of
heating and pressing a sheet-shaped member of wooden fibers
obtained by paper-machining to form a plate-shaped member.
The heat compression molding techniques used herein include
a wet pressing technique of hot pressing a wet sheet
(resulting from the wet felting technique) by a multi-stage
hot press, a wet forming/dry pressing technique of drying
the wet sheet followed by hot pressing, a dry pressing
technique of hot pressing a dry sheet (resulting from the
air felting technique) by a multi-stage hot press, and a
semi-dry pressing technique of hot pressing a semi-dry
sheet. In the method for the preparation of a wooden
fiberboard according to the invention, the steps taken until
the heat compression molding of a sheet-shaped member of
2o wooden fibers to form a plate-shaped member of wooden fibers
(referred to as fiberboard, hereinafter) may be similar to
those used in the prior art method for the preparation of a
wooden fiberboard, unless otherwise stated. The fiberboards
are those of any type including insulation boards (IB) and
hard boards (HB), though they are preferably medium density
fiberboards (MDF).
Then, in the method for the preparation of a wooden
fiberboard according to the invention, the amount of the
aqueous water repellent added is generally 0.04 to 10 g,
3o preferably 0.2 to 7 g, and more preferably 0.5 to 2 g per
100 g of the oven-dry wooden fibers. If the addition amount
is less than 0.04 g, a wooden fiberboard as heat compression
molded is often insufficiently improved in water resistance.
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CA 02392656 2002-07-05
An addition amount in excess of 10 g has an inconvenient
likelihood that wooden fibers are curled, subsequent uniform
application of the adhesive to wooden fibers is affected
thereby, a sheet-shaped member having a uniform density
distribution is not obtainable, and a decline of water
resistance improving effect and even a decline of strength
performance are incurred.
On the other hand, the amount of the water repellent
added to the adhesive is generally 0.04 to 30 g, preferably
5 to 25 g, and more preferably 15 to 20 g per 100 g of the
oven-dry wooden fibers. If the addition amount is less than
0.04 g, a wooden fiberboard as heat compression molded is
often insufficiently improved in water resistance. An
addition amount in excess of 30 g indicates a too much
i5 proportion of the weight of the water repellent (inclusive
of the adhesive) relative to the wooden fibers, leading to
an inconvenient likelihood that it becomes a factor of
interfering with the adhesive's own adhesive force, and as
previously mentioned, a sheet-shaped member having a uniform
2o density distribution is obtainable with difficulty, and a
decline of water resistance improving effect and even a
decline of strength performance are incurred. Also the cost
increases.
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CA 02392656 2002-07-05
Examples of the invention are given below together
with Comparative Examples by way of illustration and not by
way of limitation. All parts are by weight.
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 85 g (0.37
mol calculated as dimer) of a methyltrimethoxysilane
oligomer, 154 g of methanol and 5.1 g of acetic acid. With
stirring, 6.8 g (0.37 mol) of water was added to the charge,
which was stirred for 2 hours at 25°C. Then 8.9 g (0.04
mol) of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was
added dropwise. The reaction solution was heated to the
reflux temperature of methanol and reaction effected for one
hour. With an ester adapter attached, methanol was
distilled off until the internal temperature reached 110°C.
There was obtained 81 g of a pale yellow clear solution
having a viscosity of 71 mm2/s (weight average molecular
weight 1100). The content of residual methanol in the
solution was 5% by weight. This is designated Repellent 1.
Reaction was carried out as in Example 1 except that
the amount of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane
was changed to 17.8 g (0.08 mol). There was obtained 86 g
of a pale yellow clear solution having a viscosity of 116
mm2/s (weight average molecular weight 1200). The content of
residual methanol in the solution was 5% by weight. This is
designated Repellent 2.
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CA 02392656 2002-07-05
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 50.3 g
(0.37 mol) of methyltrimethoxysilane, 124 g of methanol and
5.1 g of acetic acid. With stirring, 6.8 g (0.37 mol) of
water was added to the charge, which was stirred for 2 hours
at 25°C. Then 8.9 g (0.04 mol) of N-(2-aminoethyl)-3-
aminopropyltrimethoxysilane was added dropwise. The
reaction solution was heated to the reflux temperature of
methanol and reaction effected for one hour. With an ester
s0 adapter attached, methanol was distilled off until the
internal temperature reached 110°C. There was obtained 43 g
of a pale yellow clear solution having a viscosity of 65
mm2/s (weight average molecular weight 1000). The content of
residual methanol in the solution was 6o by weight. This is
designated Repellent 3.
Exam lx~ a 4
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 60.6 g
(0.37 mol) of propyltrimethoxysilane, 144 g of methanol and
5.1 g of acetic acid. With stirring, 6.8 g (0.37 mol) of
water was added to the charge, which was stirred for 2 hours
at 25°C. Then 8.9 g (0.04 mol) of N-(2-aminoethyl)-3-
aminopropyltrimethoxysilane was added dropwise. The
reaction solution was heated to the reflux temperature of
methanol and reaction effected for one hour. With an ester
adapter attached, methanol was distilled off until the
internal temperature reached 110°C. There was obtained 51 g
of a pale yellow clear solution having a viscosity of 65
3o mm2/s (weight average molecular weight 800). The content of
residual methanol in the solution was 7~ by weight. This is
designated Repellent 4.
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CA 02392656 2002-07-05
Reaction was carried out as in Example 1 except that
17.7 g (0.08 mol) of 3-aminopropyltriethoxysilane was used
instead of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
There was obtained 90 g of a pale yellow clear solution
having a viscosity of 220 mm2/s (weight average molecular
weight 1300). The content of residual methanol in the
solution was 5~ by weight. This is designated Repellent 5.
Comparative Example 1
A 500-ml four-necked flask equipped with an aspirator
and thermometer was charged with 136 g (1.0 mol) of
methyltrimethoxysilane, 222.0 g (1.0 mol) of
N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 43.2 g
(2.4 mol) of water. With heating and stirring, stripping
was carried out through the aspirator until the internal
temperature reached 60°C. There was obtained a pale yellow
clear solution (weight average molecular weight 900). The
content of residual methanol in the solution was 1o by
weight. This is designated Repellent 6.
A mixture of 10.5 g (0.04 mol) of decyltrimethoxy-
silane, 8.8 g of methanol, 0.8 g of acetic acid and 2.2 g
(0.12 mol) of water was stirred for one hour at 25°C,
yielding a clear solution.
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 85 g (0.37
mol calculated as dimer) of a methyltrimethoxysilane
oligomer and 170 g of methanol. With stirring, the
hydrolyzate of decyltrimethoxysilane obtained above was
added dropwise to the charge, which was stirred for one hour
at 25°C. Then 5.1 g of acetic acid and 6.7 g (0.37 mol) of
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CA 02392656 2002-07-05
water were added to the solution, which was stirred for a
further one hour at 25°C. Then 17.8 g (0.08 mol) of
N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was added
dropwise. The reaction solution was heated to the reflux
temperature of methanol and reaction effected for one hour.
With an ester adapter attached, methanol was distilled off
until the internal temperature reached 110°C. There was
obtained a pale yellow clear solution (weight average
molecular weight 1300). The content of residual methanol in
1o the solution was 8~ by weight. This is designated Repellent
7.
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CA 02392656 2002-07-05
Comparative Example 3
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 85 g (0.37
mol calculated as dimer) of a methyltrimethoxysilane
oligomer and 8.9 g (0.04 mol) of N-(2-aminoethyl)-3-
aminopropyltrimethoxysilane. With stirring, 5.1 g of acetic
acid was added to the charge, which was stirred for one hour
at 25°C. There was obtained 98 g of a pale yellow clear
solution. It was attempted to dilute 10 parts of the
1o composition with 90 parts of water, but a gel formed
immediately after dilution.
Comparative Example 4
A 500-ml four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 85 g (0.37
mol calculated as dimer) of a methyltrimethoxysilane
oligomer and 8.9 g (0.04 mol) of N-(2-aminoethyl)-3-
aminopropyltrimethoxysilane. With stirring, 6.8 g (0.37
mol) of water was added to the charge. Although it was
attempted to stir the solution for 3 hours at 60°C, the
reaction solution gelled after one hour of reaction.
Combarative Example 5
A 1-liter four-necked flask equipped with a condenser,
thermometer and dropping funnel was charged with 150 g (1.l
mol) of methyltrimethoxysilane, 100 g (0.41 mol) of
3,4-epoxycyclohexylethyltrimethoxysilane, and 20 g (0.09
mol) of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
With stirring, a mixture of 100 g (5.55 mol) of water and
200 g of methanol was added dropwise to the charge over 30
minutes. The solution was stirred for a further one hour at
60°C for reaction. There was obtained 567 g of a pale
yellow clear solution. It was attempted to dilute 10 parts
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CA 02392656 2002-07-05
of the composition with 90 parts of water, but a gel formed
immediately after dilution.
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CA 02392656 2002-07-05
A composition obtained by mixing 10 parts of Repellent
1 synthesized in Example 1 and 0.5 part of 3-(trimethoxy-
silyl)propyloctadecyldimethylammonium with 89.5 parts of
water and dissolving therein is designated Repellent 8.
Exam 1p a 7
A composition obtained by mixing 10 parts of Repellent
1 synthesized in Example 1 and 2 parts of boric acid with 88
1o parts of water and dissolving therein is designated
Repellent 9.
Evaluation of storage stabilit;~
Plastic containers were charged with solutions of 10
parts of each Repellents 1 to 7 (synthesized in Examples 1-5
and Comparative Examples 1-2) diluted with 90 parts of
water, and Repellents 8 and 9 (obtained in Examples 6 and
7). Storage stability was examined at room temperature and
40°C. The results are shown in Table 1.
Repellent Appearance Storage at RT Storage at 40C
as prepared
1 Faintly turbid,clear >_ 180 days >_ 120 days
2 Faintly turbid,clear >_ 180 days >_ 120 days
3 Faintly turbid,clear >_ 180 days >_ 120 days
4 Faintly turbid,clear >_ 180 days >_ 120 days
8 Faintly turbid,clear >_ 180 days >_ 120 days
9 Faintly turbid,clear >_ 180 days ? 120 days
5 Yellow, >_ 180 days >_ 120 days
clear
6 Faintly turbid,clear gelled gelled
on on
120th 80th
day day
7 White gelled gelled
turbid on on
14th 5th day
day
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CA 02392656 2002-07-05
Use Exams
Solutions of 10 parts of Repellents 1 to 7 (obtained
in Examples 1-5 or Comparative Examples 1-2) diluted with 90
parts of water were spray coated onto plain paper sheets
having a weight of 70 g/m2, which were passed between a pair
of heating rolls for drying. It was found that the
repellents had penetrated into the interior of the plain
paper sheets. All the treated paper sheets (Sample Nos. 1
to 6) were smooth and bore 4.0 g/m2 of siloxane (calculated
on a solids basis).
Using an ink jet printer PM-750C (Seiko Epson Co.,
Ltd.), color images were printed on the treated paper
sheets. After ink drying, the printed sheets were visually
observed whether they were deformed or how the printed
z5 images were sharp. The criteria for evaluating deformation
and sharpness are given below. The results are shown in
Table 2.
(1) Discoloration of treated paper
O: not discolored
0: somewhat discolored
X: discolored
(2) Deformation of treated paper
0: no deformation or cockle
~: some cockles
X: marked cockles
(3) Sharpness of printed image
0: very sharp without bleeding
0: some bleeding
X: marked bleeding
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CA 02392656 2002-07-05
Repellent DiscolorationDeformation Sharpness
1 0 0 0
2 0 0 0
Examples 3 0 0 0
4 0 0 0
5 0 0 0
Comparative
Examples ~ X 0 X
Use Example 2
Brick pieces were dipped in solutions of 5 parts of
Repellents 1 to 7 (obtained in Examples 1-5 and Comparative
Examples 1-2) diluted with 95 parts of water (designated
Water Absorption Inhibitors 1 to 7) and aged therein, taken
out and air dried for one week at room temperature,
obtaining test samples. Tests were carried out on the
samples by the methods described below for examining the
surface state, water absorption inhibition, penetration
depth and water repellency. The results are shown in Table
3.
In another run, brick pieces were dipped in solutions
of 5 parts of Repellents 1 to 7 (obtained in Examples 1-5
and Comparative Examples 1-2) and 0.5 part of a polyether-
modified silicone surfactant (KF640 by Shin-Etsu Chemical
Co., Ltd.) diluted with 95 parts of water (designated Water
Absorption Inhibitors 1' to 7') and aged therein, taken out
and air dried for one week at room temperature, obtaining
test samples. Tests were carried out on the samples by the
methods described below for examining the surface state,
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CA 02392656 2002-07-05
water absorption inhibition, penetration depth and water
repellency. The results are shown in Table 4.
In a further run, brick pieces were dipped in an
aqueous solution of 0.5 part of a polyether-modified
silicone surfactant (KF640 by Shin-Etsu Chemical Co., Ltd.)
in 99.5 parts of water for 5 minutes as a pretreatment, then
dipped in Water Absorption Inhibitors 1 to 7 and aged
therein, taken out and air dried for one week at room
temperature, obtaining test samples. Tests were carried out
on the samples by the methods described below for examining
the surface state, water absorption inhibition, penetration
depth and water repellency. The results are shown in Table
5.
(a) Surface state, water absorption inhibition
A brick sample of 50 x 50 x 25 mm was dipped in an
aqueous solution of repellent for 30 seconds so as to give a
coverage of 100 g/m2 of the repellent over the entire
surfaces of the sample. The sample was aged for 7 days in
an atmosphere of RH 50o. The surface state of the sample
2o was visually observed and rated according to the following
criterion. Subsequently, the sample was immersed in city
water for 28 days, after which a percent water absorption
was calculated.
Surface state rating
0: no wetted color
X: wetted color
Water absorption (o) -
[(weight of brick after water absorption) -
(weight of brick before water absorption)]/
(weight of brick before water absorption) x 100
(b) Penetration depth
The brick sample which had been dipped and aged as in
Test (a) was cut into two halves. Water was applied to the
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CA 02392656 2002-07-05
cut section so that the hardened layer was readily
perceivable. The depth of penetration from the surface was
measured.
(c) Water repellency
A water droplet of 0.5 cc was dropped on the surface
of the brick sample which had been dipped and aged as in
Test (a), after which the state of the droplet was observed
and rated according to the following criterion.
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CA 02392656 2002-07-05
Rating
O: large contact angle (good water repellency)
D: moderate contact angle
X: water absorbed
Water Water Penetration
Surface Water
ample Absorption absorptiondepth
Inhibitor state (wt~) (mm) repellency
1 0 0.5 10.0 0
2 0 0.8 9.0 0
Example 3 0 1.0 8.0 0
4 0 1.2 7.0 0
5 O 0.5 11.0 0
Comparative6 X 12.0 0.2 X
Example ~ O 4.0 2.0 4
Water Water Penetration
Surface Water
ample Absorptionstate absorptiondepth repellency
Inhibitor (wt~) (mm)
1' 0 0.4 25.0 0
2' 0 0.5 17.0 0
Example 3' 0 0.8 18.0 0
4' 0 0.9 15.0 0
5' 0 0.4 30.0 0
Comparative6~ X 10.0 3.0 X
Example ~~ 0 3.5 2.0 0
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CA 02392656 2002-07-05
Water Water Penetration
Surface Water
ample Absorption absorptiondepth
Inhibitor state ~Wtg) (mm) repellency
1 0 0.4 26.0 0
2 0 0.6 17.0 0
Example 3 0 0.7 17.0 0
4 0 0.9 14.0 0
5 0 0.4 29.0 0
Comparative6 X 10.0 2.0 X
Example 7 p 4.0 2.0 D
Use Exam 1p a 3
wood pieces were dipped in solutions of 2.5 parts of
Repellents 1 to 7 (obtained in Examples 1-5 and Comparative
Examples 1-2) diluted with 97.5 parts of water (designated
Absorption Inhibitors 8 to 14) and solutions of 25 parts of
Repellents 8 and 9 (obtained in Examples 6 and 7) diluted
to with 75 parts of water (designated Absorption Inhibitors 15
and 16) and aged therein, taken out and air dried for one
week at room temperature, obtaining test samples. Tests
were carried out on the samples by the methods described
below for examining the surface discoloration and water
absorption inhibition. The results are shown in Table 6.
In another run, wood pieces were dipped in solutions
of 2.5 parts of Repellents 1 to 7 (obtained in Examples 1-5
and Comparative Examples 1-2) and 0.5 part of a polyether-
modified silicone surfactant (KF640 by Shin-Etsu Chemical
Co., Ltd.) diluted with 97.5 parts of water (designated
Water Absorption Inhibitors 8' to 14') and aged therein,
taken out and air dried for one week at room temperature,
obtaining test samples. Tests were carried out on the
samples by the methods described below for examining the
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CA 02392656 2002-07-05
surface discoloration and water absorption inhibition. The
results are shown in Table 7.
In a further run, wood pieces were dipped in an
aqueous solution of 0.5 part of a polyether-modified
silicone surfactant (KF640 by Shin-Etsu Chemical Co., Ltd.)
in 99.5 parts of water for 5 minutes as a pretreatment, then
dipped in Water Absorption Inhibitors 8 to 14 and aged
therein, taken out and air dried for one week at room
temperature, obtaining test samples. Tests were carried out
l0 on the samples by the methods described below for examining
the surface discoloration and water absorption inhibition.
The results are shown in Table 8.
(a) Surface discoloration, water absorption inhibition
A cedar sample of 50 x 50 x 21 mm and a lauan sample
of 50 x 50 x 21 mm in their entirety were dipped in an
aqueous solution of repellent for 24 hours at room
temperature and atmospheric pressure. The samples were aged
for 7 days at room temperature. The surface of the samples
was visually observed for discoloration or yellowing and
2o rated according to the following criterion. Subsequently,
the samples in their entirety were immersed in city water
for 24 hours, after which a percent water absorption was
calculated.
Surface discoloration
O: not discolored
0: slightly discolored
X: discolored
Water absorption inhibition
Water absorption (o) -
[(weight of wood after water absorption) -
(weight of wood before water absorption)]/
(weight of wood before water absorption) x 100
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CA 02392656 2002-07-05
Water Surface Water absorption
l i discoloration (wt$)
Samp absorpt
e on Cedar Lauan Cedar Lauan
inhibitor
8 0 0 10 8
9 0 0 15 12
10 0 0 11 9
Example 11 0 0 13 10
12 O 0 10 9
15 0 O 11 9
16 0 0 11 10
13 X X 47 45
Comparative14 0 D 33 26
Example
(city water)0 0 67 55
Table 7
Water Surface Water absorption
S b discoloration (wt~)
l i ~----
amp a Cedar Lauan Cedar Lauan
e sorpt
on
inhibitor
8' 0 0 8 6
9' 0 0 10 8
Example 10' 0 0 7 7
11' 0 0 11 9
12' 0 0 8 5
Comparative13' X X 37 33
Example 14' 0 O 23 19
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CA 02392656 2002-07-05
Water Surface Water absorption
discoloration (wt~)
Sample absorption
inhibitor Cedar Lauan Cedar Lauan
8 0 0 8 6
9 0 0 9 7
Example 10 0 0 8 8
11 0 0 10 9
12 0 0 7 5
Comparative13 X X 35 31
Example 14 ~ 0 24 20
Use Example 44
Wood pieces were immersed in solutions of 25 parts of
Repellents 8 and 9 (obtained in Examples 6 and 7) diluted
with 75 parts of water, aged therein, dried in air at room
temperature for one week, obtaining test samples. They were
subjected to a wood rotting test and a termite death test as
to described below. The results are shown in Table 9.
(a) Wood Rotting Test Using White and Brown Rot Fungi
For examining antibacterial/antifungal activity, a
rotting test was made on inorganic matter-composited wood
according to the Japan Wood Preservation Association (JWPA)
Standard, No. 3 (1992), Durability Test Method for Wooden
Material. After test pieces were dried and sterilized at
60°C for 48 hours, they were placed on lawns of white rot
fungus Coriolus versicolor (L. ex Fr.) Quel (IFO 30340) and
brown rot fungus Tyromyces palustris (Berk. et Curk. Murr.)
(IFO 303390) which had been fully grown in culture dishes in
a glass container. After cultivation in an incubator at
room temperature (26°C) and a relative humidity of 55 to 650
for 8 weeks, the test pieces were taken out, and the fungal
cells were wiped off form the surface. The absolute dry
-46-
CA 02392656 2002-07-05
weight of the test pieces was determined. A percent weight
loss by wood-rot fungus was calculated from the absolute dry
weight of the test pieces before the test.
(b) Subterranean Rotting Test
Untreated wood test pieces and wood test pieces which
had been treated with the water repellent were subjected to
Soxhlet extraction with acetone and water each for 24 hours.
A subterranean test of burying the test pieces in
non-sterilized soil 17 cm deep from the ground surface was
carried out for 9 months. A percent weight loss was
calculated from the absolute dry weights of each test piece
before and after the burying test, from which the progress
of decay was presumed.
(c) Termite death test
Two hundred (200) house termite individuals were
introduced in each of containers with untreated wood pieces
and water repellent-treated wood pieces and left there for
days, after which a termite death rate was determined.
20 Table 9
Wood Termite
rot
by
Wood subterranean
rot death
with rate
fungi
(%) test C%)
(%)
Sample
Cedar Lauan
WhiteBrownWhiteBrown CedarLauanCedar Lauan
rot rot rot rot
fungusfungusfungusfungus
Repellent 0.7 0.4 0.8 0.3 2.1 2.8 35 33
8
I
ti
nven
on
Repellent 2.2 1.5 3.1 2.0 8.9 7.5 100 100
9
Comparison(pity water)3.0 3.1 4.1 4.3 25.0 29.3 23 25
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CA 02392656 2002-07-05
The test piece used was a laminated veneer lumber
prepared using Radiata pine from New Zealand as a raw
material. The test piece was coated and impregnated with
the water repellent before it was measured for water
absorption prevention and dimensional stability.
The preparation of the laminated veneer lumber, the
coating and impregnation, and the measurement of water
absorption prevention and dimensional stability were
conducted as follows.
1o Using Radiata pine veneers of 3 mm thick, a laminated
veneer lumber of 9 plies having a thickness of 27 mm, a
width of 300 mm and a fiber direction of 300 mm was prepared
in a conventional way. It was aged for 7 days. One
laminated veneer lumber was then cut into three pieces
having a width of 100 mm and a fiber direction of 300 mm.
The test specimens were dried in hot air blow at 105°C for 2
hours, and then brush coated over all the surfaces (6 sides)
with an aqueous solution containing 2o Repellent 1 for
impregnation. The impregnated weight was 200 g/m2. Then the
2o test specimens were aged for a further 10 days, after which
they were subjected to tests described below as Tests 1 and
2.
Using Radiata pine veneers of 3 mm thick, a laminated
veneer lumber of 9 plies having a thickness of 27 mm, a
width of 300 mm and a fiber direction of 300 mm was prepared
in a conventional way. It was aged for 7 days. One
laminated veneer lumber was then cut into three pieces
having a width of 100 mm and a fiber direction of 300 mm.
The test specimens were dried in hot air blow at 105°C for 2
hours and aged for a further 10 days, after which it was
subjected to tests described below as Tests 1 and 2.
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CA 02392656 2002-07-05
The laminated veneer lumber prepared in Example 8 and
Comparative Example 6 were immersed in water at room
temperature for 32 hours, taken out, and dried in hot air
blow at 40°C for 16 hours. They were further immersed in
water at room temperature for 24 hours. During the process,
the weight, thickness and width of the test pieces were
measured at suitable time intervals, from which the percent
water absorption and thickness and width swelling were
computed, obtaining the results shown in FIGS. 3 to 5. It
is noted that the percent water absorption and thickness and
width swelling were calculated according to the following
equations.
Water absorption (%) - [(Wt-Wo)/Wo]x100
Wt: weight (g) of test specimen after lapse time t
Wo: weight (g) of test specimen before the test start
Thickness swelling (%) - [(Tt-To)/To]x100
Tt: thickness (mm) of test specimen after lapse time t
2o To: thickness (mm) of test specimen before the test start
Width swelling (°s) - [(WIt-WIo)/WIo]x100
WIt: width (mm) of test specimen after lapse time t
WIo: width (mm) of test specimen before the test start
Test 2
The laminated veneer lumber prepared in Example 8 and
Comparative Example 6 were immersed in water at room
temperature for 30 minutes, taken out, and allowed to stand
at room temperature for 8 hours under such conditions that
water might not evaporate from within the test piece. They
were further immersed in water at room temperature for 30
minutes, taken out, and allowed to stand at room temperature
-49-
CA 02392656 2002-07-05
for 16 hours. During the process, the weight, thickness and
width of the test pieces were measured at suitable time
intervals, from which the percent water absorption and
thickness and width swelling were computed, obtaining the
results shown in FIGS. 6 to 8. The calculation equations
used in computing are the same as described in Test 1.
Exam In a 9
The test specimen used was a plywood of five plies all
to of Radiata pine having a thickness of 12 mm (veneer
construction: 1.8+3.3+1.8+3.3+1.8 mm), a width of 50 mm and
a length of 50 mm. The test specimen was pre-dried in hot
air blow at 120°C for 2 hours. The weight of the test
specimen was measured immediately after the pre-drying,
which is the weight before the start of the test. At this
point of time, an aqueous solution containing 2% Repellent 1
was applied to all surfaces of the test piece in a coating
weight of 200 g/m2. The test specimen was aged for 10 days,
immersed in water at room temperature for 32 hours. During
2o the process, the weight of the test specimen was measured at
suitable time intervals, from which the percent water
absorption was computed according to the equation shown
below. The results are shown in FIG. 9.
Water absorption (%) - [(Wt-Wo)/Wo]x100
Wt: weight (g) of test specimen after lapse time t
Wo: weight (g) of test specimen before the test start
~,pa_rative Example 7
The same plywood as used in Example 9 was immersed in
water at room temperature for 32 hours. During the process,
the weight of the test specimen was measured at suitable
time intervals, from which the percent water absorption was
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CA 02392656 2002-07-05
computed according to the same equation as used in Example
9. The results are also shown in FIG. 9.
Example 10
An aqueous solution having a predetermined
concentration of Repellent 1 was spray added to the wooden
fibers obtained by a continuous cooking high-pressure
defibrillator, in such amounts as to provide 0.2 g, 0.5 g or
1 g of Repellent 1 per 100 g of the oven-dry wooden fiber
weight, followed by drying. Thereafter, a medium density
fiberboard was formed by heat compression molding the wooden
fibers under conventional conditions using a versatile
adhesive. After the fiberboard was aged, a specific
internal bond strength, specific bending strength, specific
Young's modulus in bending, thickness swelling by water
absorption were computed according to the fiberboard test
method of JIS A5905 and thickness swelling by a hot water
test (of immersing in hot water at 70°C for 2 hours) was
computed. The results are shown in Table 10. It is noted
2o that the specific internal bond strength, specific bending
strength, and specific Young's modulus in bending are
internal bond strength, bending strength, and Young's
modulus in bending divided by the specific gravity of the
test piece, respectively.
Comparative Example 8
A fiberboard was obtained by using the same wooden
fibers as in Example 10 and adding a predetermined amount of
commonly used acrylic wax instead of the above-mentioned
reagent. Thereafter, performance values were computed by
the same methods as in Example 10. The results are also
shown in Table 10.
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CA 02392656 2002-07-05
Repellent 1 was admixed in an adhesive such that 10 g,
15 g or 20 g of Repellent 1 was available per 100 g of in
oven-dry weight of the wooden fibers obtained by a
continuous cooking high-pressure defibrillator, followed by
drying. Thereafter, a medium density fiberboard was formed
by heat compression molding the wooden fibers under
conventional conditions. After the fiberboard was aged, a
specific internal bond strength, specific bending strength,
specific Young's modulus in bending, thickness swelling by
water absorption were computed according to the fiberboard
test method of JIS A5905 and thickness swelling by a hot
water test (of immersing in hot water at 70°C for 2 hours)
was computed. The results are shown in Table 11. It is
noted that the specific internal bond strength, specific
bending strength, and specific Young's modulus in bending
are internal bond strength, bending strength, and Young's
modulus in bending divided by the specific gravity of the
test specimen, respectively.
Gom~a-native Example 9
A fiberboard was obtained by using the same wooden
fibers as in Example 11 and adding a predetermined amount of
commonly used acrylic wax instead of the above-mentioned
reagent. Thereafter, performance values were computed by
the same methods as in Example 11. The results are also
shown in Table 11.
It is seen from these results that as compared with
the wooden fiberboards of Comparative Examples 8 and 9, the
wooden fiberboards of Examples 10 and 11 falling within the
scope of the invention are improved in specific internal
bond strength, specific bending strength, and specific
internal bond Young's modulus in bending, despite
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CA 02392656 2002-07-05
approximately equal values of water resistance (dimensional
stability).
Amount
of Thickness
reagent SPecific SpecificThicknessswelling
'
added internalSpecificYoung swelling after
s
per 100 bending modulus by
g
oven-dry stbengthstrengthin water water
wooden 2 (N/mm bending absorptiontest
(N/mm )
)
fibers (103N/mmz)(%)
(%)
(g)
0.2 1.36 82 7.3 6.1 28.9
Example 0.5 1.20 76 6.9 5.8 27.5
1.0 1.06 70 6.2 5.1 27.3
ComparativeWax 0 60 5 5 27
66 9 0 1
Example . . . .
8
Amount
of Thickness
reagent SPecific SpecificThicknessswelling
'
added internalSpecificYoung swelling after
s
per 100 bond bending modulus by hot
g
oven-dry strengthStrengthin water water
'
wooden (N/mm (N/mm bending absorptiontest
) )
fibers ( 103N/mmz)( % )
(g) (%)
10 1.26 80 7.4 6.4 30.3
Example 15 1.14 74 7.2 5.9 28.6
11
20 0.98 70 6.6 5.1 27.4
ComparativeWax 0.71 62 6 4 26
1 9 2
Example . . .
9
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CA 02392656 2002-07-05
The aqueous water repellent according to the invention
has improved water solubility and storage stability, and can
be used as a water repellent for neutral substrates simply
after dilution with water. The neutral substrates having
the repellent applied or impregnated are endowed with
satisfactory water repellency and dimensional stability.
Using the aqueous water repellent mentioned above, the
method for preparing modified plywood or modified laminated
veneer lumber according to the invention can render plywood
l0 or laminated veneer lumber termite-proof, rot-proof,
mildew-proof, water resistant, moisture resistant and
dimensional stable in accordance with the desired
performance at a particular service site, without
compromising the porosity, low specific gravity and ease of
working (machinability, nail retention, adhesion,
paintability, etc.) intrinsic to wooden panels.
Further, the method for preparing wooden fiberboards
according to the invention provides for process management
in a manufacturing factory, which enables to carry out
2o impregnating operation efficiently while preventing the
manufacturing cost from increasing.
Additionally, the invention enables mass-scale
manufacture of modified plywood and laminated veneer lumber
which can be used as building structural members clearing
the Japanese New Building Standards Act or as building
interior members and exterior members and impose a less load
to the environment upon disposal.
Moreover, the invention provides a method for
preparing a wooden fiberboard wherein a wooden fiberboard
3o having improved strength performance while maintaining water
resistance performance can be manufactured at a high
productivity and a low cost.
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