U.S. patent application number 12/682858 was filed with the patent office on 2010-09-09 for granular polyurethane resin composition and molded article of the same.
This patent application is currently assigned to Mitsui Chemicals, Inc.. Invention is credited to Daisuke Nishiguchi, Kei Ootsuki, Satoshi Yamasaki.
Application Number | 20100227985 12/682858 |
Document ID | / |
Family ID | 40567368 |
Filed Date | 2010-09-09 |
United States Patent
Application |
20100227985 |
Kind Code |
A1 |
Nishiguchi; Daisuke ; et
al. |
September 9, 2010 |
GRANULAR POLYURETHANE RESIN COMPOSITION AND MOLDED ARTICLE OF THE
SAME
Abstract
Disclosed is a granular polyurethane resin composition
containing a thermoplastic polyurethane resin which contains a hard
segment obtained by a reaction between a polyisocyanate and a chain
extender. The polyisocyanate contains isocyanate groups of
1,4-bis(isocyanatomethyl)cyclohexane in an amount of not less than
50% by more relative to the total mole number of isocyanate
groups.
Inventors: |
Nishiguchi; Daisuke; (Chiba,
JP) ; Ootsuki; Kei; (Tokyo, JP) ; Yamasaki;
Satoshi; (Chiba, JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Mitsui Chemicals, Inc.
|
Family ID: |
40567368 |
Appl. No.: |
12/682858 |
Filed: |
October 14, 2008 |
PCT Filed: |
October 14, 2008 |
PCT NO: |
PCT/JP2008/068577 |
371 Date: |
April 13, 2010 |
Current U.S.
Class: |
525/453 |
Current CPC
Class: |
C08G 18/758 20130101;
C08G 18/10 20130101; C08G 18/753 20130101; C08G 2140/00 20130101;
B29C 41/18 20130101; C08G 18/71 20130101; B29K 2075/00 20130101;
C08G 18/2825 20130101; C08G 18/3206 20130101; C08G 18/10 20130101;
C08G 18/10 20130101; C08G 18/757 20130101; B60R 13/02 20130101;
C08G 18/722 20130101 |
Class at
Publication: |
525/453 |
International
Class: |
C08G 18/00 20060101
C08G018/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2007 |
JP |
2007-268013 |
Claims
1. A granular polyurethane resin composition comprising a
thermoplastic polyurethane resin comprising a hard segment formed
by a reaction between a polyisocyanate containing isocyanate groups
of 1,4-bis(isocyanatomethyl)cyclohexane in a proportion of not less
than 50% by mole relative to the total mole number of isocyanate
groups, and a chain extender.
2. The granular polyurethane resin composition according to claim
1, having a solidification temperature, determined by a
differential scanning calorimeter, of 0 to 140.degree. C.
3. The granular polyurethane resin composition according to claim
1, having a flow start temperature, determined by a flow tester, of
100 to 180.degree. C.
4. The granular polyurethane resin composition according to claim
1, further comprising a thermally crosslinkable monomer.
5. The granular polyurethane resin composition according to claim
4, comprising a polymerization inhibitor in an amount of 0.1 to 6
parts by mass relative to 100 parts by mass of the thermally
crosslinkable monomer.
6. The granular polyurethane resin composition according to claim
1, wherein the thermoplastic polyurethane resin comprises a vinyl
monomer-modified polyol obtained by a reaction between a
high-molecular-weight polyol and a vinyl monomer.
7. The granular polyurethane resin composition according to claim
1, being used for slush molding.
8. A molded article obtained by slush molding a granular
polyurethane resin composition comprising a thermoplastic
polyurethane resin comprising a hard segment formed by a reaction
between a polyisocyanate containing isocyanate groups of
1,4-bis(isocyanatomethyl)cyclohexane in a proportion of not less
than 50% by mole relative to the total mole number of isocyanate
groups, and a chain extender.
9. The molded article according to claim 8, being an automobile
interior trim article.
Description
TECHNICAL FIELD
[0001] The present invention relates to a granular polyurethane
resin composition and a molded article thereof. More particularly,
the present invention relates to a granular polyurethane resin
composition suitable for slush molding, and a molded article formed
from the granular polyurethane resin composition.
BACKGROUND ART
[0002] Slush molding can easily form complex-shaped products,
provide uniform thickness, and achieve a good material yield, so
that slush molding is widely used for forming of automobile
interior trim articles or the like.
[0003] Soft polyvinyl chloride-based powders have been used for
slush molding materials for years. However, a plasticizer having a
temperature below the freezing point can impair the feel of the
molded article, and a skin shrinkage occurs due to time-elapsing
escape of the plasticizer, resulting in a greater dimensional
change. For this reason, the use of polyurethane resin-based
powders in place of the soft polyvinyl chloride-based powders has
been variously studied.
[0004] There has been proposed, for example, a powder composition
for slush molding contains core-shell particles having a core layer
formed from a thermoplastic polyurethane resin and a shell layer
formed from a polymer of a vinyl monomer which is made by mixing an
aqueous dispersion of a vinyl monomer with an aqueous dispersion of
a thermoplastic polyurethane and then polymerizing the vinyl
monomer and a shell layer formed by a polymer of a vinyl monomer
(see, for example, the following Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Publication No.
2005-96432
DISCLOSURE OF THE INVENTION
Problems to be Solved
[0005] However, there is a need for automobile interior trim
articles to have better texture, design, and long-term heat
resistance.
[0006] It is an object of the present invention to provide a
granular polyurethane resin composition capable of producing a
molded article having excellent texture, design, and long-term heat
resistance with good production efficiency by slush molding, and a
molded article formed from the granular polyurethane resin
composition.
Means for Solving the Problem
[0007] To achieve the above object, the granular polyurethane resin
composition of the present invention includes a thermoplastic
polyurethane resin containing a hard segment formed by a reaction
between a polyisocyanate containing isocyanate groups of
1,4-bis(isocyanatomethyl)cyclohexane in a proportion of not less
than 50% by mole relative to the total mole number of isocyanate
groups, and a chain extender.
[0008] It is preferable that the granular polyurethane resin of the
present invention has a solidification temperature, determined by a
differential scanning calorimeter, of 0 to 140.degree. C.
[0009] It is preferable that the granular polyurethane resin of the
present invention has a flow start temperature, determined by a
flow tester, of 100 to 180.degree. C.
[0010] It is preferable that the granular polyurethane resin of the
present invention further includes a thermally crosslinkable
monomer.
[0011] It is preferable that the granular polyurethane resin of the
present invention includes a polymerization inhibitor in an amount
of 0.1 to 6 parts by mass relative to 100 parts by mass of the
thermally crosslinkable monomer.
[0012] In the granular polyurethane resin of the present invention,
it is preferable that the thermoplastic polyurethane resin includes
a vinyl monomer-modified polyol obtained by a reaction between a
high-molecular-weight polyol and a vinyl monomer.
[0013] It is preferable that the granular polyurethane resin of the
present invention is used for slush molding.
[0014] The molded article of the present invention is obtained by
slush molding the above-mentioned granular polyurethane resin
composition.
[0015] It is preferable that the molded article of the present
invention is an automobile interior trim article.
EFFECT OF THE INVENTION
[0016] With the granular polyurethane resin composition of the
present invention, a molded article having excellent fusibility
during slush molding and releasability from the mold after the
molding, and having excellent texture (feel), design, and long-term
heat resistance can be produced by slush molding with good
production efficiency. Therefore, the molded article of the present
invention is excellent in texture (feel), design, and long-term
heat resistance. Accordingly, the granular polyurethane resin
composition and the molded article thereof according to the present
invention are useful in various fields involving slush molding, for
example, automobile interior trim articles.
EMBODIMENT OF THE INVENTION
[0017] The granular polyurethane resin composition of the present
invention contains a thermoplastic polyurethane resin which
contains a hard segment formed by a reaction between a
polyisocyanate (hereinafter referred to as the above-mentioned
polyisocyanate) which contains isocyanate groups of
1,4-bis(isocyanatomethyl)cyclohexane in a proportion of not less
than 50% by mole relative to the total mole number of isocyanate
groups, and a chain extender.
[0018] The thermoplastic polyurethane resin is not particularly
limited as long as it contains the hard segment made of the
above-mentioned polyisocyanate and the chain extender, and examples
thereof include thermoplastic polyurethane resins synthesized by a
reaction of the above-mentioned polyisocyanate, a
high-molecular-weight polyol (i.e., macropolyol), and a chain
extender.
[0019] In the thermoplastic polyurethane, a soft segment is formed
by a reaction between the above-mentioned polyisocyanate and a
high-molecular-weight polyol, and a hard segment is formed by a
reaction between the above-mentioned polyisocyanate and a chain
extender.
[0020] In the present invention, the above-mentioned polyisocyanate
contains isocyanate groups of 1,4-bis(isocyanatomethyl)cyclohexane
in a proportion of not less than 50% by mole, preferably not less
than 70% by mole, more preferably not less than 80% by mole, even
more preferably 90% by mole, relative to the total mole number of
isocyanate groups. Most preferably, it contains 100% by mole of
isocyanate groups thereof
[0021] 1,4-bis(isocyanatomethyl)cyclohexane includes stereoisomers
of cis-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred
to as cis-1,4 isomer) and
trans-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred to
as trans-1,4 isomer), and in the present invention,
1,4-bis(isocyanatomethyl)cyclohexane contains trans-1,4 isomers in
a proportion of preferably not less than 50% by mole, more
preferably 70% by mole, or even more preferably not less than 80%
by mole. Most preferably, it contains 90% by mole of trans-1,4
isomers.
[0022] 1,4-bis(isocyanatomethyl)cyclohexane can be produced, for
example, by the cold/hot two-stage process (direct process) or the
salt-forming process described in Japanese Unexamined Patent
Publication No. 7-309827, or by the non-phosgenation process
described in Japanese Unexamined Patent Publication No. 2004-244349
or No. 2003-212835.
[0023] Of the above-mentioned polyisocyanates, the polyisocyanate
that can be used in combination with
1,4-bis(isocyanatomethyl)cyclohexane includes, for example,
alicyclic diisocyanates such as 1,3-cyclopentane diisocyanate,
1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate,
3-isocyanatomethy1-3,5,5-trirnethyl cyclohexyl isocyanate,
4,4'-methylene-bis(cyclohexyl isocyanate), methyl-2,4-cyclohexane
diisocyanate, methyl-2,6-cyclohexane diisocyanate,
1,3-bis(isocyanatomethyl)cyclohexane,
1,3-bis(isocyanatoethyl)cyclohexane,
1,4-bis(isocyanatoethyl)cyclohexane, and 2,5- or
2,6-bis(isocyanatomethyl)norbornane and mixtures thereof. Examples
of such polyisocyanate also include aliphatic diisocyanates such as
trimethylene diisocyanate, tetramethylene diisocyanate,
pentamethylene diisocyanate, hexamethylene diisocyanate,
1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene
diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethyl
hexamethylene diisocyanate, and 2,6-diisocyanato methyl
caproate.
[0024] Further, monoisocyanate can also be used in combination as
long as it does not impair the long-term heat resistance of molded
articles. Examples of the monoisocyanate include methyl isocyanate,
ethyl isocyanate, n-hexyl isocyanate, cyclohexyl isocyanate,
2-ethylhexyl isocyanate, phenyl isocyanate, and benzil
isocyanate.
[0025] As the polyisocyanate that can be used in combination with
1,4-bis(isocyanatomethyl)cyclohexane,
3-isocyanatomethy1-3,5,5-trimethyl cyclohexyl isocyanate,
4,4'-methylene-bis(cyclohexyl isocyanate), 1,4-cyclohexane
diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 2,5- or
2,6-bis(isocyanatomethyl)norbornane and mixtures thereof, and
hexamethylene diisocyanate are preferable.
[0026] 1,3-bis(isocyanatomethyl)cyclohexane includes stereoisomers
of cis-1,3-bis(isocyanatomethyl)cyclohexane (hereinafter referred
to as cis-1,3 isomer) and
trans-1,3-bis(isocyanatomethyl)cyclohexane (hereinafter referred to
as trans-1,3 isomer), and when 1,3-bis(isocyanatomethyl)cyclohexane
is used in combination with 1,4-bis(isocyanatomethyl)cyclohexane,
1,3-bis(isocyanatomethyl)cyclohexane contains trans-1,3 isomers in
a proportion of preferably not less than 50% by mole, more
preferably 70% by mole, or even more preferably not less than 90%
by mole.
[0027] In the present invention, the high-molecular-weight polyol
is a compound having two or more hydroxyl groups and a number
average molecular weight of 400 or more, and examples thereof
include polyether polyol, polyester polyol, polycarbonate polyol,
and vinyl monomer-modified polyol.
[0028] The high-molecular-weight polyol has a number average
molecular weight of, for example, 400 to 5000, preferably 1400 to
3000, or more preferably 1500 to 2500, and a hydroxyl value of, for
example, 10 to 125 mg KOH/g.
[0029] Examples of the polyether polyol include polypropylene
glycol and polytetramethylene ether glycol.
[0030] Examples of the polypropylene glycol include addition
polymers of alkylene oxide (including a random and/or block
copolymer of two or more kinds of alkylene oxide), such as ethylene
oxide and propylene oxide, using a low-molecular-weight polyol or a
low-molecular-weight polyamine as an initiator.
[0031] The low-molecular-weight polyol is a compound having two or
more hydroxyl groups and having a number average molecular weight
of 60 to less than 400, and examples thereof include dihydric
alcohols such as ethylene glycol, propanediol, 1,4-butylene glycol,
1,3-butylene glycol, 1,2-butylene glycol, 1,6-hexandiol, neopentyl
glycol, alkane (7-22) diol, diethylene glycol, triethylene glycol,
dipropylene glycol, 1,3- or 1,4-cyclohexane dimethanol and mixtures
thereof, 1,4-cyclohexanediol, alkane-1,2-diol (C17-20),
hydrogenated bisphenol-A, 1,4-dihydroxy-2-butene,
2,6-dimethyl-1-octene-3,8-diol, and bisphenol A; trihydric alcohols
such as glycerol and trimethylolpropane; and polyhydric alcohols
having four or more hydroxyl groups such as tetramethylolmethane,
pentaerythritol, dipentaerythritol, D-sorbitol, xylitol,
D-mannitol, and D-mannite.
[0032] Examples of the low-molecular-weight polyamine include
aliphatic diamine such as ethylenediamine; and aromatic diamine
such as tolylenediamine.
[0033] Examples of the polytetramethylene ether glycol include a
ring-opening polymerization product obtained by cationic
polymerization of tetrahydrofuran, and amorphous polytetramethylene
ether glycol obtained by copolymerizing the above-mentioned
dihydric alcohol with a polymerization unit of tetrahydrofuran.
[0034] Examples of the polyester polyol include a polycondensation
product obtained by allowing the above-mentioned dihydric alcohol
and a polybasic acid to react under known conditions.
[0035] Examples of the polybasic acid include carboxylic acids such
as oxalic acid, malonic acid, succinic acid, methylsuccinic acid,
glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane,
3-methyl-3-ethyl glutaric acid, azelaic acid, sebacic acid, and
other aliphatic dicarboxylic acids (of 11 to 13 carbon atoms),
hydrogenated dimer acid, maleic acid, fumaric acid, itaconic acid,
orthophthalic acid, isophthalic acid, terephthalic acid, toluene
dicarboxylic acid, dimer acid, and HET acid; and acid anhydrides
and acid halides derived from these carboxylic acids.
[0036] Examples of the polyester polyol include polycaprolactone
polyol and polyvalerolactone polyol, which are obtained by
ring-opening polymerization of lactones, such as c-caprolactone and
.gamma.-valerolactone, using the above-mentioned dihydric alcohol
as an initiator; and lactone-based polyester polyol obtained by
copolymerizing these polyols with the above-mentioned dihydric
alcohol.
[0037] Examples of the polycarbonate polyol include a ring-opening
polymerization product of ethylene carbonate using the
above-mentioned dihydric alcohol as an initiator; and amorphous
polycarbonate polyol obtained by copolymerizing a ring-opening
polymerization product and dihydric alcohol such as 1,4-butanediol,
1,5-pentanediol, or 1,6-hexandiol.
[0038] The vinyl monomer-modified polyol can be obtained by a
reaction between the above-mentioned high-molecular-weight polyol
and a vinyl monomer. Containing of the vinyl monomer-modified
polyol as a high-molecular-weight polyol allows molded articles to
have improved light resistance and a moist texture. Further, in the
production process, preparation of the thermoplastic polyurethane
resin as a dispersion to be described later can prevent adhesion to
a production equipment.
[0039] Among the above-mentioned high-molecular-weight polyols, a
high-molecular-weight polyol which does not contain a carbon-carbon
double bond (high-molecular-weight polyol selected from polyether
polyol, polyester polyol, and polycarbonate polyol) is preferable,
or a polyester polyol which does not contain a carbon-carbon double
bond is more preferable.
[0040] Examples of the vinyl monomer include alkyl (meth)acrylate
such as ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl
acrylate, isononyl acrylate, 2-ethylhexyl acrylate, methyl
methacrylate, butyl methacrylate, cyclohexyl methacrylate, and
2-ethylhexyl methacrylate; and vinyl cyanide or vinylidene cyanide
such as acrylonitrile and methacrylonitrile. These vinyl monomers
can be used alone or in combination of two or more kinds. Among
them, alkyl (meth)acrylate is preferable. Preferably, more than 50%
by mass of alkyl (meth)acrylate is contained in the vinyl
monomer.
[0041] The above-mentioned high-molecular-weight polyol and the
vinyl monomer are allowed to react, for example, by blending a
vinyl monomer in an amount of, for example, 2 to 50 parts by mass,
preferably, 5 to 30 parts by mass, or more preferably 10 to 30
parts by mass, per 100 parts by mass of the above-mentioned
high-molecular-weight polyol, and adding a radical polymerization
initiator thereto.
[0042] The radical polymerization initiator that may be used
includes, for example, persulfate, organic peroxide, and azo
compound.
[0043] Examples of the persulfate include sodium persulfate,
potassium persulfate, and ammonium persulfate.
[0044] Examples of the organic peroxide include peroxy ketals such
as 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di
(t-hexylperoxy)-3,3,5-trimethylcyclohexane,
1,1-di(t-butylperoxy)cyclohexane,
n-butyl-4,4-di(t-butylperoxy)valerate, 2,2-di(t-butylperoxy)butane,
1,1-di(t-butylperoxy)-2-methylcyclohexane,
1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, and
2,2-di(4,4-dibutylperoxycyclohexyl)propane; dialkyl peroxides such
as di-t-butyl peroxide; diacyl peroxides such as dilauroyl
peroxide, di-(3-methylbenzoyl)peroxide,
benzoyl(3-methylbenzoyl)peroxide, and dibenzoyl peroxide; and
peroxyesters such as 1,1,3,3-tetramethylbutyl
peroxy-2-ethylhexanoate, 2,5-dimethyl
-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexyl
peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-hexyl
peroxy isopropyl monocarbonate, t-butyl peroxy laurylate, t-butyl
peroxy isopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl
monocarbonate, and 2,5-dimethyl-2,5-di(benzoylperoxy)hexane.
[0045] Examples of the azo compound include
azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile),
2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis
(2-methylpropionate), 2,2'-azobis [(2-(2-imidazoline-2-yl)propane],
dimethyl methylpropaneisobutyrate,2,2,7-azobis [N-(2-carb
oxyl)-2-methylpropioneamidine]tetrahydrate,2,2'-azobis[2-methyl-N-[1,1-bi-
s(hydroxymethyl)-2-hydroxyethyl] propionamide],
2,2'-azobis[N-(2-hydroxyethyl)-2-methylpropanamide],
2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), and 1,1'-azobis
[cyclohexane-1-carbonitrile].
[0046] These radical polymerization initiators can be used alone or
in combination of two or more kinds. Among them, organic peroxides
are preferable, or peroxyketals are more preferable.
[0047] The radical polymerization initiator is added in an amount
of, for example, 3 to 10 parts by mass, or preferably 4 to 9 parts
by mass, per 100 parts by mass of the high-molecular-weight
polyol.
[0048] In this reaction, for example, the monomer solution obtained
by mixing the vinyl monomer and the radical polymerization
initiator is added dropwise to the high-molecular-weight polyol
under an inert gas atmosphere, and the mixture is allowed to react,
for example, at a reaction temperature of 80 to 160.degree. C., or
preferably 100 to 140.degree. C. for a reaction time of 1 to 10
hours, or preferably 2 to 8 hours.
[0049] A vinyl monomer-modified polyol can be obtained by the above
reaction. The vinyl monomer-modified polyol has a number average
molecular weight of, for example, 900 to 5000, or preferably 1000
to 3000, and a hydroxyl value of, for example, 20 to 80 mg
KOH/g.
[0050] Further, in the synthesis of the thermoplastic polyurethane
resin, the above-mentioned low-molecular-weight polyol, a monol,
and/or a monoamine can be used in combination with the
high-molecular-weight polyol.
[0051] Examples of the monol include methanol, ethanol, propanol,
butanol, 2-ethylhexyl alcohol, other alkanols (C5-38) and aliphatic
unsaturated alcohol (9-24), alkenyl alcohol, 2-propen-1-ol,
alkadienol (C6-8), and 3,7-dimethy1-1,6-octadien-3-ol.
[0052] Examples of the monoamine include dimethylamine,
diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine,
diisobutylamine, di-t-butylamine, dihexylamine, 2-ethylhexylamine,
3-methoxypropylamine, 3-ethoxypropylamine, 3-(2-ethylhexyloxypropy
lamine), 3-(dodecyloxy)propylamine, N,N-dimethyl
1,3-propanediamine, and morpholine.
[0053] The monol and/or monoamine is/are blended as required in
order to adjust the molecular weight of the thermoplastic
polyurethane resin.
[0054] In the present invention, examples of the chain extender
include low-molecular-weight polyols such as the above-mentioned
dihydric alcohols and the above-mentioned trihydric alcohols; and
diamine such as alicyclic diamine and aliphatic diamine.
[0055] Examples of the alicyclic diamine include
1-amino-3-aminomethy1-3,5,5-trimethylcyclohexane,
bis-(4-aminocyclohexyl)methane, diaminocyclohexane,
3,9-bis(3-aminopropyl )-2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3-
and 1,4-bis(aminomethypcyclohexane and mixtures thereof.
[0056] Examples of the aliphatic diamine include ethylenediamine,
propylenediamine, hexamethylenediamine, hydrazine,
1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane.
[0057] These chain extenders can be used alone or in combination of
two or more kinds. Among them, the above-mentioned dihydric
alcohols are preferable, or ethylene glycol, 1,3-propanediol,
1,4-butanediol, and 1,6-hexamethylene glycol are more
preferable.
[0058] The thermoplastic polyurethane resin can be synthesized with
each of the above-mentioned components (i.e., the above-mentioned
polyisocyanate, the high-molecular-weight polyol, and the chain
extender as essential components, and the low-molecular-weight
polyol, the monol, and the monoamine as optional components) by a
known synthesizing process such as one-shot process and prepolymer
process. Preferably, the thermoplastic polyurethane resin is
synthesized by the prepolymer process.
[0059] In the one-shot process, the above-mentioned components are
allowed to react by simultaneously blending the above-mentioned
polyisocyanate and the other components (the high-molecular-weight
polyol and the chain extender, and as optional components, the
low-molecular-weight polyol, the monol, and the monoamine) such a
ratio that the equivalent ratio of the isocyanate group in the
above-mentioned polyisocyanate to the active hydrogen group
(hydroxyl group and amino group) in the other components is in the
range of, for example, 0.8 to 1.1, or preferably 0.9 to 1.05.
[0060] This reaction is continued, for example, at a reaction
temperature of 40 to 260.degree. C., or preferably 80 to
220.degree. C. for a reaction time of 0.5 to 10 hours, or
preferably 2 to 8 hours under a nitrogen atmosphere.
[0061] In the reaction, if necessary, a catalyst such as amines or
organometallic compounds, or a solvent can be added.
[0062] As the catalyst, an organometallic compound is preferable,
and examples of the organometallic compound include tin acetate,
tin octylate, tin oleate, tin laurate, dibutyl tin diacetate,
dimethyl tin dilaurate, dibutyl tin dilaurate, dioctyl tin
dilaurylate, dibutyl tin dichloride, lead octanoate, lead
naphthenate, nickel naphthenate, cobalt naphthenate, octenate
copper, and bismuth-based catalyst.
[0063] These catalysts can be used alone or in combination of two
or more kinds, and the catalyst is added in an amount of, for
example, 0.001 to 5 parts by mass, or preferably 0.01 to 3 parts by
mass, per 100 parts by mass of the high-molecular-weight
polyol.
[0064] Examples of the solvent include aliphatic hydrocarbons and
alicyclic hydrocarbons such as hexane, heptane, octane, pentane,
and cyclohexane; esters including alkyl esters such as methyl
acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, and amyl
acetate, and ether esters such as ethylene glycol monomethyl ether
acetate, ethylene glycol monoethyl ether acetate, ethylene glycol
mono-n-butyl ether acetate, and ethyl ethoxy propionate; ketones
such as acetone, methyl ethyl ketone, methyl isobutyl ketone,
methyl amyl ketone, and cyclohexanone; and aromatic hydrocarbons
such as toluene, xylene, and ethylbenzene.
[0065] These solvents can be used alone or in combination of two or
more kinds, and are blended at an appropriate ratio according to
the viscosity of the reaction system or the like.
[0066] Then, in the one-shot process, the thermoplastic
polyurethane resin thus obtained is, if necessary, crushed by a
known method and thereafter, a freeze crushing method is performed
to produce the granular polyurethane resin composition of the
present invention in the form of powder. Even in the one-shot
process, a vinyl monomer polymer, a thermally crosslinkable
monomer, a polymerization inhibitor and a known additive, which are
described later, can be appropriately blended by kneading or other
means, so that the granular polyurethane resin composition of the
present invention can be obtained in the form of powder.
[0067] In the prepolymer method, first, the above-mentioned
polyisocyanate and the components other than the chain extender
(i.e., the above-mentioned polyisocyanate and the
high-molecular-weight polyol as essential components, and the
low-molecular-weight polyol, the monol, and the monoamine as
optional components) are allowed to react to synthesize an
isocyanate group-terminated prepolymer, and the isocyanate
group-terminated prepolymer and the chain extender are then allowed
to react.
[0068] The isocyanate group-terminated prepolymer is synthesized in
the following manner. The above-mentioned polyisocyanate, the
high-molecular-weight polyol, and if necessary, the
low-molecular-weight polyol, the monol, and the monoamine are
allowed to react by blending them at such a ratio that the
equivalent ratio (isocyanate group/active hydrogen group) of the
isocyanate group in the above-mentioned polyisocyanate to the
active hydrogen group (hydroxyl group and amino group) in the
high-molecular-weight polyol, the low-molecular-weight polyol, the
monol, and the monoamine is in the range of, for example, 1.1 to 4,
or preferably 1.4 to 2.5.
[0069] When the above equivalent ratio is less than 1.1, the
thermoplastic polyurethane resin has excessively high molecular
weight, which may deteriorate moldability. On the other hand, when
it exceeds 4, the molded article may become hard, which may impair
the texture.
[0070] This reaction is continued, for example, at a reaction
temperature of 40 to 180.degree. C., or preferably 60 to
140.degree. C. for a reaction time of 0.5 to 10 hours, or
preferably 2 to 8 hours under a nitrogen atmosphere, and the
reaction is terminated at the time when a desired isocyanate group
content (e.g., 1 to 12% by weight) is obtained in the reaction
system. In the reaction, if necessary, the above-mentioned catalyst
or solvent can also be added.
[0071] Subsequently, the isocyanate group-terminated prepolymer and
the chain extender are blended at such a ratio that the equivalent
ratio (active hydrogen group/isocyanate group) of the active
hydrogen group (amino group and hydrogen group) in the chain
extender to the isocyanate group in the isocyanate group-terminated
prepolymer is in the range of, for example, 0.8 to 1.1, or
preferably 0.9 to 1.05, and the blended mixture is subjected to
chain extension reaction, so that a thermoplastic polyurethane
resin is produced.
[0072] In the chain extension reaction, for example, the isocyanate
group-terminated prepolymer is dispersed in a non-aqueous
dispersion medium or an aqueous dispersion medium to prepare a
dispersion of the isocyanate group-terminated prepolymer, and a
chain extender is added at once or in portions to the
dispersion.
[0073] Examples of the non-aqueous dispersion medium include the
above-mentioned solvents, and examples of the aqueous dispersion
include water, or mixed solutions of water and alcohols (e.g.,
methanol, ethanol, etc.).
[0074] The blending amount of the non-aqueous dispersion medium or
the aqueous dispersion medium is in the range of, for example, 10
to 200 parts by mass, or preferably 20 to 150 parts by mass, per
100 parts by mass of the isocyanate group-terminated *polymer.
[0075] An emulsifier, for example, a nonionic surfactant such as
polyoxyethylene alkyl ether, or an anionic surfactant such as
sodium polyoxyethylene alkyl ether sulfate can also be added to the
dispersion.
[0076] Further, a dispersion stabilizer can be added to the
dispersion in order to prevent the sedimentation of the dispersed
phase. Examples of the dispersion stabilizer include dispersing
agents described in Japanese Unexamined Patent Publication No.
2004-169011, such as resin obtained by dehydration condensation of
an alkenyl succinic anhydride and a polyol or a polyester polyol;
alkyd resin obtained by dehydration condensation of a part of the
remaining OH groups of the polyester, which is obtained by
dehydration condensation of dicarboxylic acid and pentaerythritol,
with fatty acids; resin obtained by grafting an ethylenically
unsaturated monomer onto a polyol obtained by dehydration
condensation of an unsaturated bond-containing dicarboxylic acid
and a polyol or a polyester polyol, and thereafter masking an OH
group; and resin obtained by masking an OH group of a polyol
obtained by dehydration condensation of an unsaturated
bond-containing dicarboxylic acid and a polyol or a polyester
polyol, and thereafter grafting an ethylenically unsaturated
monomer.
[0077] The blending amount of the emulsifier or the dispersion
stabilizer is in the range of, for example, 0.05 to 5 parts by
mass, preferably 0.1 to 3 parts by mass, or more preferably 0.15 to
1.5 parts by mass, per 100 parts by mass of the isocyanate
group-terminated prepolymer.
[0078] The chain extension reaction is performed, for example, at a
reaction temperature of 10 to 100.degree. C., or preferably 20 to
90.degree. C. for a reaction time of 0.5 to 8 hours, or preferably
2 to 6 hours. In the reaction, if necessary, the above-mentioned
catalyst can be added.
[0079] Thus, the thermoplastic polyurethane resin can be obtained
as a dispersion.
[0080] In the chain extension reaction, without dispersing the
isocyanate group-terminated prepolymer in the non-aqueous
dispersion medium or the aqueous dispersion medium, the isocyanate
group-terminated prepolymer and the chain extender can be allowed
to react directly with each other.
[0081] The thermoplastic polyurethane resin thus obtained has a
concentration of the hard segment formed by the reaction between
the above-mentioned polyisocyanate and the chain extender in the
range of preferably 4 to 20% by mass, or more preferably 5 to 15%
by mass. When the hard segment concentration of the thermoplastic
polyurethane resin is within the above-mentioned range, mold
releasability and fusibility can be balanced.
[0082] The hard segment concentration can be calculated, for
example, from the blending formulation (preparation) of each of the
components by the following equation:
[0083] [Chain extender (g)+(chain extender (g)/molecular weight of
chain extender (g/mol)).times.average molecular weight of
polyisocyanate (g/mol)]/(high-molecular-weight polyol
(g)+polyisocyanate (g)+chain extender (g)+optional component
(low-molecular-weight polyol (g)+monol (g)+monoamine
(g))).times.100
[0084] Alternatively, the hard segment concentration can be
actually measured, for example, by solid NMR or solution NMR of the
composition for slush molding. The specific measurement method is
described in, for example, Satoshi Yamasaki et. al, "Effect of
aggregation structure on rheological properties of thermoplastic
polyurethanes, "Polymer, 48 vol., pp. 4793-4803, 2007.
[0085] The granular polyurethane resin composition of the present
invention can contain, a vinyl monomer polymer, a thermally
crosslinkable monomer, a polymerization inhibitor, or the like
according to the purposes and applications, as well as the
thermoplastic polyurethane resin.
[0086] In the present invention, the vinyl monomer polymer is, for
example, a copolymer of an aromatic vinyl monomer and
.alpha.,.beta.-ethylenically unsaturated carboxylic acid alkyl
ester, and can be obtained by subjecting the aromatic vinyl monomer
and the .alpha.,.beta.-ethylenically unsaturated carboxylic acid
alkyl ester to a radical copolymerization reaction.
[0087] Examples of the aromatic vinyl monomer include styrene-based
monomers such as styrene and .alpha.-methylstyrene; alkyl
vinylbenzene such as vinyltoluene and ethylvinylbenzene; and
polycyclic aromatic monovinyl monomers such as
vinylnaphthalene.
[0088] These aromatic vinyl monomers can be used alone or in
combination of two or more kinds. Among them, styrene is
preferable.
[0089] Examples of the .alpha.,.beta.-ethylenically unsaturated
carboxylic acid alkyl ester include acrylate, and examples of the
acrylate include alkyl (meth)acrylate such as ethyl acrylate,
propyl acrylate, butyl acrylate, cyclohexyl acrylate, isononyl
acrylate, 2-ethylhexyl acrylate, methyl methacrylate, butyl
methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl
methacrylate. Examples of the .alpha.,.beta.-ethylenically
unsaturated carboxylic acid alkyl ester further include vinyl
cyanides or vinylidene cyanides such as acrylonitrile and
methacrylonitrile.
[0090] These .alpha.,.beta.-ethylenically unsaturated carboxylic
acid alkyl esters can be used alone or in combination of two or
more kinds. Among them, methyl methacrylate and butyl methacrylate
are preferable.
[0091] The aromatic vinyl monomer and the
.alpha.,.beta.-ethylenically unsaturated carboxylic acid alkyl
ester are subjected to a radical copolymerization reaction in the
following manner. The aromatic vinyl monomer in a proportion of 35
to 70% by mass, or preferably 45 to 65% by mass and the
.alpha.,.beta.-ethylenically unsaturated carboxylic acid alkyl
ester in a proportion of 30 to 65% by mass, or preferably 35 to 55%
by mass, are blended with respect to the total amount of their
vinyl monomers and a radical polymerization initiator is added
thereto to radically copolymerize the mixture.
[0092] Examples of the radical polymerization initiator include
those radical polymerization initiators mentioned above. The
radical polymerization initiator is added in an amount of, for
example, 0.1 to 10 parts by mass, or preferably 1 to 7 parts by
mass, per 100 parts by mass of the total amount of vinyl
monomers.
[0093] In the radical copolymerization reaction, if necessary,
chain transfer agents, for example, mercaptans such as t-dodecyl
mercaptan and 2-ethylhexyl thioglycolate; or styrene dimers such as
.alpha.-methylstyrene dimer can also be added. The chain transfer
agent is added in an amount of, for example, 0 to 10 parts by mass,
preferably 0.01 to 5 parts by mass, or more preferably 0.01 to 2
parts by mass, per 100 parts by mass of the total amount of vinyl
monomers.
[0094] In the radical copolymerization reaction, the vinyl monomer
is allowed to react, for example, at a reaction temperature of 20
to 150.degree. C., or preferably 30 to 120.degree. C. for a
reaction time of 1 to 20 hours, or preferably 2 to 15 hours.
[0095] The vinyl monomer polymer is synthesized on the
above-mentioned conditions separately from the thermoplastic
polyurethane resin, and the synthesized product can be blended with
the thermoplastic polyurethane resin or a dispersion thereof. The
vinyl monomer polymer can be synthesized in the following manner. A
vinyl monomer, a radical polymerization initiator, and, if
necessary, a chain transfer agent (if necessary, as a monomer
liquid preliminarily mixed therewith) are blended with an
isocyanate group-terminated prepolymer or a thermoplastic
polyurethane resin, or a dispersion thereof, so that the vinyl
monomer polymer can be synthesized in the dispersion on the
above-conditions.
[0096] The vinyl monomer polymer is blended in an amount of, for
example, 5 to 40 parts by mass, preferably 6 to 30 parts by mass,
or more preferably 6 to 20 parts by mass, per 100 parts by mass of
the thermoplastic polyurethane resin.
[0097] In the present invention, the thermally crosslinkable
monomer is a compound having a plurality of ethylenically
unsaturated bonds, and examples thereof include alkanediol
di(meth)acrylate such as ethylene glycol di(meth)acrylate,
propyleneglycol di(meth)acrylate, butylene glycol di(meth)acrylate,
pentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate,
hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, and
oligoethylene glycol di(meth)acrylate; alkane polyol
poly(meth)acrylate such as trimethylolpropane tri(meth)acrylate,
glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,
dipentaerythritol penta(meth)acrylate, and dipentaerythritol
hexa(meth)acrylate; unsaturated carboxylic acid diallyl ester, such
as diallyl maleate, diallyl fumarate, and diallyl itaconate;
urethane di(meth)acrylate; and polybutadiene di(meth)acrylate.
Among them, dipentaerythritol penta(meth)acrylate and
dipentaerythritol hexa(meth)acrylate are preferable.
[0098] These thermally crosslinkable monomers can be used alone or
in combination of two or more kinds. Among them, alkane polyol
poly(meth)acrylate is preferable. The thermally crosslinkable
monomer is blended in an amount of, for example, 1 to 10 parts by
mass, or preferably 1 to 7 parts by mass, per 100 parts by mass of
the thermoplastic polyurethane resin.
[0099] Specifically, the thermally crosslinkable monomer is blended
with, for example, the thermoplastic polyurethane resin or a
dispersion thereof.
[0100] In the present invention, examples of the polymerization
inhibitor include quinones such as p-benzoquinone, p-methoquinone,
naphthoquinone, phenanthraquinone, toluquinone, and
2,5-diphenyl-p-benzoquinone; hydroquinones such as hydroquinone,
p-t-butylcatechol, 2,5-di-t-butylhydroquinone,
mono-t-butylhydroquinone, and 2,5-di-t-amyl hydroquinone; and
phenols such as p-methoxy phenol and di-t-butyl paracresol
hydroquinone monomethyl ether.
[0101] These polymerization inhibitors can be used alone or in
combination of two or more kinds. Among them, hydroquinone and
p-methoxy phenol are preferable. The polymerization inhibitor is
blended in an amount of, for example, 0.1 to 6 parts by mass,
preferably 0.1 to 5 parts by mass, or more preferably 0.1 to 4
parts by mass, per 100 parts by mass of the thermally crosslinkable
monomer.
[0102] When the number of parts by mass of the polymerization
inhibitor is less than 0.1 parts by mass, color irregularity, feel,
and further long-term heat resistance may deteriorate. On the other
hand, when it exceeds 6 parts by mass, color irregularity,
mechanical strength, and long-term heat resistance may
deteriorate.
[0103] Specifically, the polymerization inhibitor is blended with,
for example, the thermoplastic polyurethane resin or a dispersion
thereof.
[0104] As for the granular polyurethane resin composition of the
present invention, when the dispersion is prepared from a
non-aqueous dispersion medium, for example, solids are separated,
for example, by separating means such as filtration to obtain a
granular polyurethane resin composition in the form of powder. On
the other hand, when the dispersion is prepared from an aqueous
dispersion medium, for example, solids are separated, for example,
by spray drying to obtain a granular polyurethane resin composition
in the form of powder. Further, when the isocyanate
group-terminated prepolymer and the chain extender are allowed to
react directly with each other without dispersing in a non-aqueous
dispersion medium or an aqueous dispersion medium, a granular
polyurethane resin composition is obtained in the form of powder,
for example, by a freeze crushing method.
[0105] Other known additives such as plasticizer, antiblocking
agent, heat-resistant stabilizer, light-resistant stabilizer,
releasing agent, or further, antioxidant, ultraviolet absorber,
pigment, dye, lubricant, filler, or hydrolysis inhibitor can
optionally be added to the granular polyurethane resin of the
present invention. These additives may be added during synthesis of
each component or may be added during mixing and dissolving of each
of the components, and further, they can also be added after
separation and drying of the granular polyurethane resin of the
present invention.
[0106] The granular polyurethane resin of the present invention has
a volume-average particle size of, for example, 50 to 300 .mu.m, or
preferably, 80 to 200 .mu.m. When the volume-average particle size
thereof is less than 50 .mu.m, irregularities may occur during
molding due to deterioration in powder flowability. On the other
hand, when the volume-average particle size exceeds 300 .mu.m,
pinholes may be formed in a surface of the molded article.
[0107] The granular polyurethane resin composition of the present
invention has a solidification temperature, which is determined by
a differential scanning calorimeter, of, for example, 0 to
140.degree. C., preferably 10 to 120.degree. C., or more preferably
20 to 110.degree. C. When the solidification temperature is within
the above-mentioned range, the aggregation of the hard segment in a
cooling process is high, achieving improvement in mold
releasability and shape retention of the molded article required
for slush molding. Specifically, the solidification temperature can
be determined by the method to be described later in Examples.
[0108] The granular polyurethane resin composition of the present
invention has a flow start temperature, which is determined by a
flow tester, of, for example, 100 to 180.degree. C., preferably 100
to 170.degree. C., or more preferably 110 to 160.degree. C. When
the flow start temperature is within the above-mentioned range, the
fusibility required for slush molding can be improved.
Specifically, the flow start temperature can be determined by the
method to be described later in Examples.
[0109] With the granular polyurethane resin composition of the
present invention, a molded article having excellent fusibility
during slush molding and releasability from the mold after the
molding, and having excellent texture (feel), design, and long-term
heat resistance can be produced by slush molding with good
production efficiency. Therefore, the molded article of the present
invention is excellent in texture (feel), design, and long-term
heat resistance. Accordingly, the granular polyurethane resin
composition and the molded article thereof according to the present
invention are useful in various fields involving slush molding, for
example, furniture such as sofas and bedding; toys; sporting goods;
and toner binders, and are particularly useful in automobile
interior trim articles. The granular polyurethane resin composition
of the present invention is also useful in fields other than those
involving slush molding, for example, toner binders.
EXAMPLES
[0110] While in the following, the present invention is described
with reference to Preparation Examples, Examples, and Comparative
Examples, the present invention is not limited to any of them.
Preparation Example 1 (Preparation Method of
1,4-bis(isocyanatomethyl)cyclohexane)
[0111] As a raw material, 1,4-bis(aminomethyl)cyclohexane
(manufactured by Mitsubishi Gas Chemical Company, Inc.) having a
trans/cis ratio of 93/7 determined by .sup.13C-NMR was used to
perform cold/hot two-stage phosgenation method under normal
pressure.
[0112] Specifically, a stirring rod, a thermometer, a phosgene
inlet tube, a dropping funnel, and a condenser tube were attached
to a flask, and the flask was charged with 400 parts by mass of
ortho dichlorobenzene. While the flask was cooled with cold water,
the temperature in the flask was lowered to 10.degree. C. or below,
and 280 parts by mass of phosgene was introduced thereinto from the
phosgene inlet tube. The dropping funnel was charged with a mixed
solution of 100 parts by mass of 1,4-bis(aminomethyl)cyclohexane
and 500 parts by mass of ortho dichlorobenzene, and the mixed
solution was added into the flask over 30 minutes. During this
time, the temperature in the flask was maintained at 30.degree. C.
or below. After completion of the addition, a white slurry-like
liquid was formed in the flask. Again, the reaction temperature was
increased to 150.degree. C. with introducing phosgene, and the
reaction was continued at 150.degree. C. for 5 hours. The reaction
solution in the flask became a pale-brown transparent liquid.
[0113] After completion of the reaction, nitrogen gas was
introduced at a temperature of 100 to 150.degree. C. at a flow rate
of 10 L/hour for degassing.
[0114] The ortho dichlorobenzene solvent was distilled away under
reduced pressure and a fraction having a boiling point of 138 to
140.degree. C./0.7 KPa was further sampled by vacuum
distillation.
[0115] Thus, 123 parts by mass (90% yield) of
1,4-bis(isocyanatomethyl)cyclohexane was obtained in the form of a
colorless and transparent liquid.
[0116] The resulting 1,4-bis(isocyanatomethyl)cyclohexane had a
purity, which was determined by gas chromatography, of 99.9%, a hue
of 5 in APHA, and a trans/cis ratio, which was determined by
.sup.13C-NMR, of 93/7.
Preparation Example 2 (Preparation Method of Dispersion Stabilizer
(I))
[0117] A three-neck flask equipped with a stirrer was charged with
2000 parts by mass of adipate polyester polyol (manufactured by
MITSUI CHEMICALS POLYURETHANES, INC., trade name: U-2610) and 98
parts by mass of maleic anhydride. The mixture was then gradually
heated under a nitrogen flow and was thereafter stirred at
150.degree. C. for 20 hours. Further, the mixture was gradually
heated to 170.degree. C. under a reduced pressure of 2.66 kPa with
nitrogen bubbling, and stirred at that temperature for 5 hours, to
obtain an unsaturated bond-containing polyol.
[0118] After the temperature was increased to 70.degree. C. under a
nitrogen atmosphere, 200 parts by mass of ethyl isocyanate was
gradually added dropwise to 1300 parts by mass of the unsaturated
bond-containing polyol. The mixture was then allowed to react at a
temperature of 75 to 80.degree. C. for 6 hours to synthesize an
unsaturated bond-containing compound having a urethane bond at the
end of the molecule.
[0119] Next, the unsaturated bond-containing compound was subjected
to reduced pressure treatment on the conditions of 130.degree. C.
and 0.66 kPa or less. Further, 11547 parts by mass of butyl acetate
was added to 6077 parts by mass of the unsaturated bond-containing
compound to prepare a uniform solution. Thereafter, the atmosphere
was fully replaced with nitrogen and the solution was heated to
110.degree. C.
[0120] A monomer solution obtained by preliminarily mixing 21270
parts by mass of lauryl methacrylate and 1100 parts by mass of
benzoyl peroxide was added dropwise at 110.degree. C. for about 1
hour under a nitrogen atmosphere. The mixture was allowed to react
at a temperature of 110 to 120.degree. C. for 2 hours and then
further allowed to react at 130.degree. C. for 2 hours. As a
result, a dispersion stabilizer (I) having a solid content of about
65% by mass was obtained.
Preparation Example 3 (Preparation Method of Vinyl Monomer-Modified
Polyol A)
[0121] A reactor equipped with a stirrer, a dropping apparatus, and
a condenser was charged with 315.5 parts by mass of adipate
polyester polyol (manufactured by MITSUI CHEMICALS POLYURETHANES,
INC., trade name: Takelac U-2024) having a number average molecular
weight of 2000, which was preliminarily subjected to reduced
pressure dehydration treatment, and the mixture was heated to
117.degree. C. with stirring under a nitrogen atmosphere.
[0122] Subsequently, a monomer solution obtained by preliminarily
mixing 63.11 parts by mass of n-butyl methacrylate (manufactured by
Wako Pure Chemicals Industries, Ltd.) and 21.5 parts by mass of
PERHEXA C (S) (manufactured by NOF Corporation, organic peroxide
obtained by diluting 1,1-di(t-butylperoxy)cyclohexane with a
hydrocarbon-based solvent so as to have a purity of 70%) under a
nitrogen atmosphere was added dropwise at a temperature of 117 to
121.degree. C. to the reactor maintaining at the above-mentioned
temperature over about 4 hours.
[0123] Thereafter, the added mixture was aged to react at
120.degree. C. for 4 hours, and the monomer was distilled off at a
temperature of 115 to 125.degree. C. with nitrogen bubbling under a
reduced pressure of 1.33 kPa or less for about 5 hours until the
distillate was no longer observed.
[0124] Thus, a vinyl monomer-modified polyol A having a hydroxyl
value of 42.2 mg KOH/g and an acid value of 0.7 mg KOH/g was
synthesized.
Example 1
[0125] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
84.25 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 13.40 parts by mass of the
1,4-bis(isocyanatomethyl)cyclohexane (hereinafter abbreviated as
1,4-BIC) prepared in Preparation Example 1 as a polyisocyanate, and
the mixture was heated to a temperature of 80 to 85.degree. C. with
thoroughly stirring.
[0126] Subsequently, the reaction vessel was charged at once with
0.2399 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 1.98% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0127] Thereafter, the reaction vessel was charged at once with
0.4528 parts by mass of the dispersion stabilizer (I) and 68.57
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0128] Then, as a chain extender, 2.156 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0129] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0130] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0131] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Example 2
[0132] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
81.61 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.49 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, 13.21 parts by mass of 1,4-BIC as
a polyisocyanate, and 1.99 parts by mass of
4,4'-methylenebis(cyclohexylisocyanate) (manufactured by Sumika
Bayer Urethane Co., Ltd., trade name: Desmodur W, abbreviated as
H12MDI), and the mixture was heated to a temperature of 80 to
85.degree. C. with thoroughly stirring.
[0133] Subsequently, the reaction vessel was charged at once with
0.2342 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 2.7% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0134] Thereafter, the reaction vessel was charged at once with
0.4482 parts by mass of the dispersion stabilizer (I) and 67.98
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0135] Then, as a chain extender, 2.899 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0136] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0137] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0138] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Example 3
[0139] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
84.25 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.50 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 13.42 parts by mass of 1,4-BIC
as a polyisocyanate, and the mixture was heated to a temperature of
80 to 85.degree. C. with thoroughly stirring.
[0140] Subsequently, the reaction vessel was charged at once with
0.2398 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 2.00% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0141] Thereafter, the reaction vessel was charged at once with
0.4523 parts by mass of the dispersion stabilizer (I) and 68.53
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0142] Then, as a chain extender, 2.159 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 3 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0143] Thereafter, the reaction temperature of the dispersion was
lowered to 60.degree. C., 2.003 parts by mass of a mixture of
dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate
(manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA)
as a thermally crosslinkable monomer and 1.000 part by mass of
p-methoxyphenol (abbreviated as MQ) as a polymerization inhibitor
per 100 parts by mass of the thermally crosslinkable monomer were
charged in the dispersion of the thermoplastic polyurethane resin,
and mixed for 2 hours.
[0144] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0145] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0146] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Example 4
[0147] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
63.39 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
21.71 parts by mass of polyol A in Preparation Example 3, 0.50
parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.48 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 12.58 parts by mass of 1,4-BIC
as a polyisocyanate, and the mixture was heated to a temperature of
80 to 85.degree. C. with thoroughly stirring.
[0148] Subsequently, the reaction vessel was charged at once with
0.2253 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 1.88% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0149] Thereafter, the reaction vessel was charged at once with
0.4518 parts by mass of the dispersion stabilizer (I) and 68.62
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0150] Then, as a chain extender, 2.025 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 3 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0151] Thereafter, the reaction temperature of the dispersion was
lowered to 60.degree. C., and 2.996 parts by mass of a mixture of
dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate
(manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA)
as a thermally crosslinkable monomer and 1.000 part by mass of
p-methoxyphenol (abbreviated as MQ) as a polymerization inhibitor
per 100 parts by mass of the thermally crosslinkable monomer were
charged in the dispersion of the thermoplastic polyurethane resin,
and mixed for 2 hours.
[0152] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0153] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0154] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Comparative Example 1
[0155] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
63.05 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, 12.23 parts by mass of 1,4-BIC,
and 14.95 parts by mass (i.e., the molar ratio of 1,4-BIC/1,3-BIC
is 45/55) of 1,3-bis(isocyanatomethyl)cyclohexane (manufactured by
MITSUI CHEMICALS POLYURETHANES, INC., trade name: TAKENATE 600,
abbreviated as 1,3-BIC) as a polyisocyanate, and the mixture was
heated to a temperature of 80 to 85.degree. C. with thoroughly
stirring.
[0156] Subsequently, the reaction vessel was charged at once with
0.3532 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol
and 0.0278 parts by mass of dibutyltin dilaurate (manufactured by
Wako Pure Chemicals Industries, Ltd.) as a urethanizing catalyst.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 9.62% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0157] Thereafter, the reaction vessel was charged at once with
0.4185 parts by mass of the dispersion stabilizer (I) and 63.38
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0158] Then, as a chain extender, 9.402 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0159] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0160] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0161] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Comparative Example 2
[0162] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
63.06 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 27.19 parts by mass of
1,3-bis(isocyanatomethyl)cyclohexane (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., trade name: TAKENATE 600) as a
polyisocyanate, and the mixture was heated to a temperature of 80
to 85.degree. C. with thoroughly stirring.
[0163] Subsequently, the reaction vessel was charged at once with
0.3532 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol
and 0.0268 parts by mass of dibutyltin dilaurate (manufactured by
Wako Pure Chemicals Industries, Ltd.) as a urethanizing catalyst.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 9.63% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0164] Thereafter, the reaction vessel was charged at once with
0.4176 parts by mass of the dispersion stabilizer (I) and 63.38
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0165] Then, as a chain extender, 9.401 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0166] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0167] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0168] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Comparative Example 3
[0169] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
77.35 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.50 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.48 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 16.88 parts by mass of
hexamethylene diisocyanate (TAKENATE 700 manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., abbreviated as HDI) as a
polyisocyanate, and the mixture was heated to a temperature of 80
to 85.degree. C. with thoroughly stirring.
[0170] Subsequently, the reaction vessel was charged at once with
0.6150 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 5.00% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0171] Thereafter, the reaction vessel was charged at once with
0.4378 parts by mass of the dispersion stabilizer (I) and 66.38
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0172] Then, as a chain extender, 5.199 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0173] Next, this dispersion was cooled to 30.degree. C. or below
and the solid was separated by filtration.
[0174] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0175] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Comparative Example 4
[0176] A reaction vessel equipped with a nitrogen introducing tube,
a thermometer, a condenser tube, and a stirrer was charged with
64.48 parts by mass of Takelac U-2024 (manufactured by MITSUI
CHEMICALS POLYURETHANES, INC., number average molecular weight:
2000, adipate polyester polyol) as a high-molecular-weight polyol,
0.51 parts by mass of IRGANOX 245 (manufactured by Ciba Specialty
Chemicals K. K.) as an antioxidant, 0.51 parts by mass of Tinuvin
213 (manufactured by Ciba Specialty Chemicals K. K.) as a
benzotriazol type ultraviolet absorber, 0.49 parts by mass of
Tinuvin 765 (manufactured by Ciba Specialty Chemicals K. K.) as a
hindered amine light stabilizer, and 28.48 parts by mass of
4,4'-methylenebis(cyclohexylisocyanate) (manufactured by Sumika
Bayer Urethane Co., Ltd., trade name: Desmodur W) as a
polyisocyanate, and the mixture was heated to a temperature of 80
to 85.degree. C. with thoroughly stirring.
[0177] Subsequently, the reaction vessel was charged at once with
0.3159 parts by mass of 2-ethylhexyl alcohol (manufactured by Wako
Pure Chemicals Industries, Ltd., abbreviated as 2-EtOH) as a monol
and 0.0285 parts by mass of dibutyltin dilaurate (manufactured by
Wako Pure Chemicals Industries, Ltd.) as a urethanizing catalyst.
After the reaction was continued for about 2 hours, it was
confirmed that the isocyanate content had dropped to 6.52% by mass,
so that an isocyanate group-terminated prepolymer was obtained.
[0178] Thereafter, the reaction vessel was charged at once with
0.4301 parts by mass of the dispersion stabilizer (I) and 65.31
parts by mass of n-heptane which were preliminarily mixed, and the
isocyanate group-terminated prepolymer was dispersed over 1
hour.
[0179] Then, as a chain extender, 6.640 parts by mass of
1,4-butanediol (manufactured by Wako Pure Chemicals Industries,
Ltd., abbreviated as 1,4-BD) was charged therein, and the mixture
was thereafter allowed to react at that temperature for 5 hours, to
obtain a dispersion of thermoplastic polyurethane resin.
[0180] Next, the dispersion was cooled to 30.degree. C. or below
and the solid was collected by filtration.
[0181] Subsequently, a dryer was charged with 100 parts by mass of
the solid, 0.5 parts by mass of TSF-451-3000 (silicone oil
manufactured by GE Toshiba Silicones Co., Ltd.) as a releasing
agent, and 0.3 parts by mass of an antiblocking agent, and the
mixture was dried at 40.degree. C. for 3 hours with stirring under
reduced pressure. Thereafter, the resulting content was cooled to
25.degree. C. or below and then discharged to produce a granular
polyurethane resin.
[0182] To 100 parts by mass of the granular polyurethane resin thus
produced, 0.6 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-817) and 0.4 parts by mass of a carbon black/calcium carbonate
dispersion (manufactured by Sumika Color CO., LTD., trade name:
PV-801) as pigments were supplied in a Henschel mixer and stirred
at a rotational speed of 700 min.sup.-1 for 1 minute. Then, the
mixture was screened through a 48 mesh sieve and further through a
200 mesh sieve, and the granular polyurethane resin was
colored.
Evaluation of Physical Properties
[0183] Solidification temperature, mold releasability and
dimensional change of the skin, and flow start and end temperatures
of the granular polyurethane resin composition (hereinafter
abbreviated as each powder) obtained in each of Examples and
Comparative Examples were measured by the following methods.
[0184] Further, after an embossing mold was heated to 240.degree.
C., 300 g of each powder was sprayed onto the mold having a
vertical length of 15 cm and a horizontal length of 15 cm, and
allowed to stand for 8 seconds. Thereafter, unfused excess powder
was discarded. Subsequently, the mold was allowed to stand at
250.degree. C. for 60 seconds, and then water-cooled to be molded
into an about 1-mm-thick sheet. Then, the physical properties of
the molded article were determined by the following methods. The
results are shown in Table 1.
[0185] Each powder had a volume-average particle size of about 110
to 180 .mu.m. The volume-average particle size of each powder was
determined by measuring the volume-average particle size of each
powder which was replaced with and dispersed in n-heptane, using a
particle size analyzer (manufactured by Nikkiso Co., Ltd., model:
MICROTRAC HRA). The average particle size refers to a value of 50
cumulative percentages in the particle size distribution curve on a
volume percentage basis.
<Mold Releasability (Solidification Temperature (.degree.
C.))>
[0186] The mold releasability was determined using a differential
scanning calorimeter (DSC, manufactured by SEIKO Instruments Inc.,
trade name: SSC5200H Disk Station and DSC220C).
[0187] About 9 mg of powder was weighed to be determined as a
sample, and alumina was sampled to be determined as a reference.
After these samples were placed on the DSC measuring apparatus, the
temperature was lowered from room temperature to -90.degree. C. at
a rate of 10.degree. C./min under a nitrogen flow having a nominal
flow rate of 40 N ml/min, maintained at -90.degree. C. for 5
minutes, then heated from -90.degree. C. to 250.degree. C. at a
rate of 10.degree. C./min, and maintained at 250.degree. C. for 5
minutes. Subsequently, the temperature was lowered from 250.degree.
C. to -90.degree. C. at a rate of 10.degree. C./min. The
temperature at an exothermic peak derived from powders observed in
this temperature lowering process was determined as solidification
temperature. In Table 1, "n. d." represents not detected.
<Mold Releasability (Mold Releasability and Dimensional Change
(%) of Skin (Sheet))>
[0188] In the above-mentioned operation method, slush molding was
performed, the mold was cooled to room temperature, and the sheet
was released from the mold. The sheet was allowed to stand in a
laboratory at 23.degree. C. for about 24 hours, and then the sheet
and the mold was compared in terms of vertical length. The vertical
length of the molded sheet was measured based on the vertical
length of the mold and was evaluated according to the following
criteria. When the dimensional change after the mold release was
small, the mold releasability was judged to be good.
[0189] When the vertical length of the sheet after released from
the mold was set to L2 (mm) and the vertical length of the mold was
set to L1 (mm), the dimensional change was defined as an absolute
value determined by the following formula:
|(L2-L1)/L1.times.100|.
(Evaluation Criteria)
[0190] "A": The dimensional change of the sheet was less than
1.5%.
[0191] "B": The dimensional change of the sheet was 1.5% or more
and 2.5% or less.
[0192] "C": The dimensional change of the sheet exceeded 2.5%, and
a tuck remarkably remained on the surface of the sheet.
<Fusibility (Flow Start Temperature (.degree. C.) and Flow End
Temperature (.degree. C.))>
[0193] Using a flow tester (manufactured by Shimadzu Corp., trade
name: CFT-500D), the fusibility was determined with a die having a
length of 10 mm and a bore diameter of 1.0 mm Weighed was 1.7 g of
powder and charged in the measuring apparatus. Thereafter, a flow
start temperature (Tfb) (.degree. C.) and a flow end temperature
(Tend) (.degree. C.) were measured on the conditions of a load of
196 N (20 kgf) and a heating rate of 2.5.degree. C./min. In Table
1, the difference (Tend-Tfb (.degree. C.)) between the flow end
temperature (Tend) and the flow start temperature (Tfb) was shown
together.
<Fusibility (Skin Rear Surface Gloss)>
[0194] The gloss of the rear surface (unembossed surface) of the
sheet was measured using a gloss meter (manufactured by Nippon
Denshoku Industries Co., Ltd., Model type: Gloss Meter VG2000). It
was judged that the fusibility of the powder was high with high
gloss and some powders remained unfused with low gloss.
<Feel (Bending Wrinkles)>
[0195] A sheet being bent by 180.degree. was kept for 20 seconds,
then returned to its original state, and allowed to stand for a
whole day and night. The bent portion was visually observed and
evaluated in accordance with the following criteria. When the sheet
was hard or limp, bending wrinkles were likely to be observed.
(Evaluation Criteria)
[0196] "A": Bending wrinkles were not observed.
[0197] "B": Bending wrinkles were slightly observed.
[0198] "C": Bending wrinkles were apparently observed.
<Design>
[0199] As for the sheet obtained by molding each powder and then
allowing the molded powder to stand in a thermostatic chamber at
23.degree. C. and 55% RH for two months, the existences of
blooming, embossing flow, and a gloss change were visually
evaluated.
(Evaluation Criteria)
[0200] "A": Blooming, embossing flow, and a gloss change were not
observed.
[0201] "B": Blooming and embossing flow were not observed but a
gloss change was observed.
[0202] "C": Either blooming or embossing flow was observed.
<Design (Analysis of Polyisocyanate)>
[0203] The surface of the sheet obtained by molding each powder and
then allowing the molded powder to stand in a thermostatic chamber
at 23.degree. C. and 55% RH for two months was wiped off with
cotton wool preliminarily moistened with methanol. Thereafter, the
cotton wool was washed with methanol and was determined as a
sample. The polyisocyanate in the methanol impregnated in the
sample was analyzed by GC-MS on the following conditions. It should
be noted that the detection limit of GC-MS was 10 ppm, and when it
detected not less than 10 ppm, it was judged as "detected", and
when less than 10 ppm, "less than detection limit".
[0204] GC-MS apparatus: Manufactured by Hewlett Packard Co., trade
name: HP6890 type GC and HP5973 type MS detector
[0205] Column: Manufactured by Frontier Laboratories Ltd., trade
name: UADX30-30M-0.15F
[0206] Carrier gas: Helium
[0207] Injection temperature: 250.degree. C.
[0208] Column temperature: Kept at 50.degree. C. for 5 minutes and
then heated up to 350.degree. C. at a rate of 10.degree. C./min
<Heat Resistance (Gloss, Embossing Flow, and Strength
Retention)>
[0209] Each of the sheets obtained by slush molding was allowed to
stand in a constant temperature room at 23.degree. C. and 55% RH
for two weeks, thereafter allowed to stand in a hot air circulation
type oven for 500 hours, and subjected to heat treatment. After the
heat treatment, the gloss of the sheet surface was measured. The
gloss was measured using a gloss meter (manufactured by Nippon
Denshoku Industries Co., Ltd., Model type: Gloss Meter VG2000). It
was judged that the appearance changed with high gloss. Further,
the existence of the embossing flow after the heat treatment was
visually observed. When the embossing flow was observed, the heat
resistance was judged to be low.
[0210] Further, the tensile strength of the sheet before and after
the heat treatment was measured, and the strength retention (%) was
calculated by dividing the tensile strength of the sheet after the
heat treatment by the tensile strength before the heat treatment,
and then multiplying the result by 100.
[0211] According to the method described in JIS K-6251, the tensile
strength of the sheet was determined by stamping out a test piece
with a JIS-No. 4 dumbbell, and measuring it using a tensile
strength testing machine (manufactured by ORIENTEC Co., LTD, trade
name: universal tensile testing machine RTA-500) at a tensile speed
of 300 mm/min.
TABLE-US-00001 TABLE 1 Comp. Comp. Comp. Comp. Composition Ex. 1
Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Thermoplastic
Polyurethane Resin (part by mass) 100 100 100 100 100 100 100 100
Polyiso- 1,4-BIC (part by mass) 13.40 13.21 13.42 12.58 12.23 -- --
-- cyanate 1,3-BIC (part by mass) -- -- -- -- 14.95 27.19 -- -- HDI
(part by mass) -- -- -- -- -- -- 16.88 -- H12MDI (part by mass) --
1.99 -- -- -- -- -- 28.48 Chain Extender 1,4-BD (part by mass)
2.156 2.899 2.159 2.025 9.402 9.401 5.199 6.640 High- Takelac
U-2024 84.25 81.16 84.25 63.39 63.05 63.06 77.35 64.48 Molecular-
(part by mass) Weight Polyol Polyol A (part by mass) -- -- -- 21.71
-- -- -- -- Monol 2-EtOH (part by mass) 0.2399 0.2342 0.2398 0.2253
0.3532 0.3532 0.6150 0.3159 Thermally Crosslinkable KAYARAD DPHA --
-- 2.003 2.996 -- -- -- -- Monomer (part by mass) Polymerization
Inhibitor MQ -- -- 1.000 1.000 -- -- -- -- (part by mass per 100
parts by mass of thermally crosslinkable monomer) Evaluation Mold
Solidification 59.5 71.8 62.3 60.2 n.d. n.d. 78 n.d. Releasability
Temperature (.degree. C.) Mold Releasability A A A A B C A C of
Skin Dimensional Change (%) 0.53% 1.33% 0.67% 0.80% 2.33% 3.33%
1.00% 2.87% Fusibility Flow Start Temperature 130.2 125.7 131.3
138.3 137.7 136.1 143.9 102.8 (Tfb) (.degree. C.) Flow End
Temperature 145.9 142.8 150.1 158.1 175.1 172.5 172.2 123.6 (Tend)
(.degree. C.) Tend - Tfb (.degree. C.) 15.7 17.1 18.8 19.8 37.4
36.4 28.3 20.8 Skin Rear Surface Gloss 35 45 37 34 18 8 11 72 Feel
Bending Wrinkles A A A A A B C A Design A A A A B C C B Analysis of
Less than Less than Less than Less than Less than Less than
Detected Less than Polyisocyanate detection detection detection
detection detection detection detection limit limit limit limit
limit limit limit Heat Gloss After Heat 2.2 2.3 2.1 2.0 35 30 2.2
60 Resistance Treatment Embossing Flow Not Not Not Not Observed
Observed Not Observed After Heat Treatment observed observed
observed observed observed Strength Retention After 76.3% 72.1%
78.6% 79.6% 23.2% 12.3% 76.6% 13.4% Heat Treatment (%)
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 restrictively. 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
[0212] The granular polyurethane resin composition of the present
invention is suitably used for slush molding.
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