CA2009931A1

CA2009931A1 - Moldable resin composition

Info

Publication number: CA2009931A1
Application number: CA 2009931
Authority: CA
Inventors: Shuji Iwamaru; Yoshito Fujiki
Original assignee: Individual
Current assignee: Toagosei Co Ltd
Priority date: 1989-02-14
Filing date: 1990-02-13
Publication date: 1990-08-14
Also published as: JPH02212538A

Abstract

ABSTRACT OF THE DISCLOSURE
A moldable resin composition is discloses, which has a 200°C heat stability of 60 minutes of more and which comprises a polymer, calcium carbonate and a heat stabilizer, the polymer being produced by polymerizing (i) monomeric vinyl chloride or (ii) a monomer mixture composed of (a) monomeric vinyl chloride and (b) a monomer which is copolymerizable therewith and which yields a homopolymer having a glass transition temperature below 30°C, in the presence of 10 to 200 parts by weight, per 100 parats by weight of said monomeric vinyl chloride (i) or said monomer mixture (ii), of a themoplastic polyurethane elastomer which is soluble in monomeric vinyl chloride at the polymerization condition and has a softening point in the range of from 20 to 100°C. The resin composition can provide a molded articles containing very few fisheyes and having a smooth surface.

Description

- 20~9931 MOLDABLE RESIN COMPOSITION
FIELD OF THE INVENTION
The present invention relates to a moldable resin composition which comprises an urethane-vinyl chloride type eopolymer having moderate pliability without the need to add pl~sticizers.
BACRGROUND OF THE INVENTION
Recently, polymers that are produced by polymerizing monomeric vinyl chloride or a monomer mixture composed of monomeric vinyl chloride and a monomer which is copolymerizable ~ J
therewith and whieh yields a homopolymer having a glass transition temperature below 30C, in the presence of 10 to 200 parts by weight, per 100 parts by weight of the monomeric vinyl chloride or the monomer mixture, of a thermoplastic polyurethane elastomer whieh i8 soluble in monomerie vinyl ehloride and whieh has a softening point in the range of from -20 to 100C (hereafter referred to as urethane-vinyl ehloride type copolymers) were developed as a resin showing moderate pliability without the ineorporation of plasticizers and having ~:
moldability almost eomparable to that of non-rigid vinyl chloride resins, as described in U.S. Patent 4,672,095 and U.X.
Patent 2107326B. Due to their moderately pliable nature, which copolymers obtained following such prior art possess even `~ :
without a plastieizer, sueh urethane-vinyl ehloride type eopolymers are used in various ways as a ma~or resin eomponent ' ~

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-` 20~9931 of a variety of flexible molded articles that have sufered in the part from plasticizer bleeding.
Examples of applications of the above-described urethane-vinyl chloride type copolymer~ resins for use in molding include medical devices, food wrapping films or flexible hoses (U.~. Patent 2107326B), spring cords (JP-A-62-229718), and cables for VTR cameras (JP-A-62-229712).
(The term ~JP-A~ a8 used herein means an ~unexamined published Japanese patent application".) Application examples further include automotive side moldings comprising the above-described urethane-vinyl chloride type copolymers (JP-A-64-85759 and JP-A-1-101248) As methods for obtaining these resin molded articles, there have been proposed, for example, a process in which suitable amounts of calcium stearate and zinc stearate are added as stabilizers to a urethane-vinyl chloride type copolymer and the resulting copolymer is formed into films at a temperature of about 170C by means of an extruder for PVC
(U.R.Patent 2107326B), and a process in which hoses are formed from the urethane-vinyl chloride type copolymer under the same conditions as those for the above film forming process except that barium stearate and zinc stearate are added as stabilizers (U.K.Patent 2107326B). The molded articles obtained by these processes are excellent in hardne~s, tensile strenqth, .
elongation, and other mechanical properties and also an non-`~ 2 ~--` ~ 20Q9931 toxic, and show good weatherabllity, oil resistance, chemical resistance and transparency.
However, the above described urethane-vinyl chloride type copolymers have defects in that since they contain many fisheyes as compared with poly(vinyl chloride), molded articles obtained therefrom have a poor surface appearances.
SUMMARY OF THE INVENTION
It is, therefore, an ob~ect of the present invention is to provide moldable resin composition~, which comprise an urethane-vinyl chloride type copolymer obtained by polymerizing monomeric vinyl chloride in the presence of a thermoplastic polyurethane elastomer and which contain very few fisheyes and, hence, yield molded articles having good surface appearances.
In order to overcome the above described problem, the present inventors previously compounded resin compositions by incorporating various kinds of inorganic fillers into a urethane-vinyl chloride type copolymer and studied the moldability of these re~in compo~itions. As a result, it was found that the ~ind of inorganic filler greatly affects the number of fisheye~ and the surface appearance of the molded articles, with calcium carbonate only being most effective in reducing fisheyes and improving surface appearance. However, even by the use of calcium carbonate as an inorganic filler for the copolymers, the amount of fi~heyes could not be reduced to or below the desired level.
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In view of the fact that in the case of poly(vinyl chloride) and similar polymers, flsheyes can usually be effectively dimini~hed by thoroughly kneading the molten polymer together with an inorganic filler, the present inventors tried this method on ur~thane-vinyl chloride type copolymers, but the decrease in the amount of fisheyes was insufficient. They then thought that if the urethane-vinyl chloride copolymer, to which the present invention relates, were kneaded even more thoroughly than poly(vinyl chloride), it would be poss~ble to effectively diminish fisheyes. They conducted intensive research based on the above theory, but satisfactory results could not be obtained.
The present inventor~ then tried to find the reason why kneading was ineffective in diminishing fisheyes in the urethane-vinyl chloride type copolymers, and as a result, found that ~ince urethane-vinyl chloride type copolymers are thermally unstable compared to poly(vinyl chloride), they undergoes pyrolysis due to the heat supplied or generated during kneading and the resulting decomposition products caused new fisheyes. Further, they have finally found that fisheyes can be greatly diminished in a very effective manner by imparting good heat stabiiity to a resin composition comprising a urethane-vinyl chloride type copolymer, such heat stability being 60 minutes or more in terms of 200C heat stability as measured in accordance with the method provided for in JIS

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21~9~31 6723. The present invention was completed based on the above findings.
That is, the present invention is a moldable resin composition having a 200C heat stability of 60 minutes or more, which comprises a urethane-vinyl chloride type copolymer, calcium carbonate and a heat ~tabilizer, the urethane-vinyl chloride type copolymer being produced by polymerizing (i) monomeric vinyl chloride or (ii) a monomer mixture composed of (a) monomeric vinyl chloride and (b) a monomer which is copolymerizable therewith and which yields a homopolymer having a glass transition temperature below 30C, in the presence of 10 to 200 part~ by weight, per 100 parts by weight of the monomeric vinyl chloride (i) or the monomer mixture (ii), of a thermopla~tic polyurethane elastomer which i8 ~oluble in monomeric vinyl chloride and has a softening point in the range of from 20 to 100C.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be explained below in detail. -The Urethane-VinYl Chloride TvDe Co~olYmer The urethane-vinyl chloride type copolymer employed in .
.
this invention is, as described above, produced by polYmerizing - :
monomeric vinyl chloride (hereafter referred to as MVC) or a monomer mixture composed of MVC and a monomer which is copolymerizable therewith and which yields a homopolymer having :: ' ' f' . ',, ,.. .'.','::' .` ' ,' ' ~ ,, ''', ".', " '. '' .': ` , ~ ' .: i,,,: .: : .~:.:::. :.:, : : - ,,: . . ~ .. : -20~9931 a glass transition temperature below 30C (the N~C and the monomer mixture are hereafter collectively referred to as "MVC-based monomer~), in the presence of 10 to 200 parts by weight, per 100 parts by weight of the MVC-based monomer, of a thermoplastic polyurethane ela~tomer soluble in MVC and having a ~oftening point in the range of from 20 to 100C (the polyurethane elastomer iB hereafter referred to as ~MvC-soluble TPU~). The thus produced urethane-vinyl chloride type copolymer~ are assumed to be graft copolymers. Such urethane-vinyl chloride type copolymers can easily be produced according to, for example, the proce~s as disclosed in the above mentioned U.S. Patent 4,672,095 and U.R. Patent 2107326B.
The urethane-vinyl chloride type copolymers of this invention generally has a number average molecular weight of from 10,000 to 1,000,000 and preferably from 30,000 to 200,000.
An exemplary urethane-vinyl chloride type copolymer preferably employed in this invention is one obtained by conducting the polymerization of the MVC-based monomer in the presence of the MVC-soluble TPU and also in the presence of an epoxy compound which ~ an epoxy heat ~tabilizer which also functions al~o as a plasticizer, such as an epoxidized vegetable or animal oil, an epoxidized ester (e.g., butyl, propyl, octyl, etc.) of an higher fatty acid (e.g., oleic acid, linoleic acid, etc.), an epoxidized diester of a higher fatty acid, or a 6-membered alicyclic epoxide. The epoxy compound ''~

20~9931 used in this invention preferably has an oxirane oxygen content of 2 wt% or more.
The amount of the epoxy compound incorporated into the polymerization system is generally 30 parts by weight or less, preferably 2 to 20 partY by weight, per 100 parts by weight of the MVC-based monomer. If the amount of the epoxy compound is greater than 30 parts by weight, part of the epoxy compound may bleed out onto the surfaces of final molded articles to impair their surface quality.
Specific examples of the epoxy compound which can be preferably incorporated into the polymerization system includes epoxidized vegetable or animal oils such as epoxidized soybean oil, epoxidized safflower oil, epoxidized cottonseed oil, epoxidized linseed oil, epoxidized whale oil, epoxidized tall oil, epoxidized corn oil, epoxidized sunflower oil, epoxidized camellia oil, and epoxidized fish oil; epoxidized esters of higher fatty acid such as alkyl epoxy stearates, alkyl epoxy oleates, alkyl epoxy elaidate~, alkyl e~ters of epoxy tall oil fatty acid, alkyl esters of epoxy rice bran oil fatty acid, alkyl esters of epoxy soybean oil fatty acid, and alkyl esters of epoxy linseed oil fatty acid; epoxidized diesters of higher fatty acids such as epoxidized propylene glycol esters of oleic acid, epoxidized 1,3-butylene glycol esters of oleic acid, epoxidized propylene glycol esters of tall oil fatty acid, and epoxidized 1,3-butylene glycol ester of tall oil fatty acid; 6-_ 7 -3 . . .
~'' . ' ".

20~9931 membered ~licyclic expoxide~ such a8 alkyl (Cll2) epoxy hexahydrophthalates, epoxy alkyl epoxy hexahydrophthalate~, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3 , 4 - e p o x y - 6 - m e t h y l c y c l o h e x y l m e t h y l - 3 , 4 -epoxy-6-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate; and other epoxy compounds such a~ epoxy stearyl benzoate and methyl epoxy stearyl phthalate.
Due to its micro-dispersion effect, the epoxy compound, which is incorporated into the polymerization sy~tem for obtaining the urethane-vinyl chloride type copolymer to be employed in this invention, serves to improve the heat ~tability of the resin composition produced and also to achieve greatly improved moldability, or it can dimini~h unmelted subst~nce~, i.e., fisheye~, developing on the ~urfaces of final molded articles.
The MVC-~oluble TPU u~ed in the polymerization for producing the urethane-vinyl chloride type copolymer contained in the resin composition of thi~ invention i8 a thermopla~tic polyurethane elastomer which is substantially soluble in the NVC-based monomer under the polymerization conditions for producing the urethane-vinyl chloride type copolymer and which has a softening point in the range of from 20 to 100C, preferably from 30 to 60C.
The solution vi~cosity of the MVC-soluble TPU to be u~ed for producing the urethane-vinyl chloride type copolymer .

is preferably from 30 to 1,000 cps, more preferably from 50 to 400 cps, most preferably from 100 to 300 Cp8, as measured a 20 wt~ solution in methyl ethyl ketone.
Thermoplastic polyurethane elastomers having softening points higher than 100C are di~advantageous in that it i~
difficult to dissolve them in the MVC-based monomer, while those with softening points below 20C are not preferable because the resulting urethane-vinyl chloride type copolymer has low tensile strength and poor heat resistance.
In the pre~ent invention, softening points are measured by the constant-temperature-rise method employing a Koka flow teister under the following conditions.
Measuring Conditions:
Apparatus ; ~oka flow tester manufactured by Shimadzu Corporation, Japan Nozzle size ; 1 mm~ x 2 mmL
Load ; 30 kg Temperature rise rate; 3C/min.
The above-de~icribed MVC-soluble TPU can be produced by reacting a diisocyanate with 0.95 to 1.05 mol per mol of the diisocyanate of a polyester diol obtained by the esterification of an aliphatic dicarboxylic acid preferably having 2 to 10 carbon atom~, (e.g., adipic acid) with one or more kinds of diols preferably having 2 to 8 carbon atoms (e.g., butanediol, neopentyl glycol, pentanediol, and hexanediol)~ or a polyether _ g _ , .
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, , . - ::, .. ,i. , "~ ,.. , :.. , ~., ,. ,: ,,, . ,, ,, . " :. . , . .: , 20~9931 diol obtained by the polyconden~ation of a diol preferably having 2 to 8 carbon atoms (e.g., ethylene glycol, propylene glycol, and butanediol).
The number average molecular weights of the polyester diol and polyether diol are preferably in the range of from 500 to 4,000. Preferred ex~mples of the diisocyanate are aliphatic dilsocyanate~ such as tetramethylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.
Polyurethane elastomers obtained from aliphatic diisocyanate~ have non-yellowing properties and give final molded articles with good ultraviolet stability, whereas polyurethane elastomers other than those with non-yellowing properties produce, through polymerization, urethane-vinyl chloride type copolymers which give final molded articles prone to undergo di~coloration.
As the MVC-soluble TPU, commercially available ones may also be used, such as Pandex T-5265 and Pandex T-525, both trade names of thermoplastic polyurethanes manufactured by ~:
Dainippon Ink ~ Chemicals, Incorporated, Japan.
In performing the polymerization of the MVC-based monomer, the amount of the NVC-soluble TPU present in the polymerization system is from 10 to 200 parts by weight, preferably from 20 to 150 parts by weight, per 100 parts by weight of the NVC-based monomer introduced. If the amount of the MVC-soluble TPU is below 10 parts by weight, satisfactory : :

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:`: ' ' ' - 20~9931 pliability cannot be imparted to the resulting polymer. On the other hand, if the amount thereof exceeds 200 parts by weight, the result is unfavorably low polymerization rate~.
According to the present invention, the content of the MVC-soluble TPU in the urethane-vinyl chloride type copolymer produced i8 preferably from 10 to 80% by weight, more preferably from 17 to 6S% by weight. Thi~ is because contents thereof below 10~ by weight often result in unsatisfactory pliability, whlle content~ thereof exceeding 80~ by weight often result in poor heat re~istance and are also disadvantageous from the economical standpoint because the costs are too high.
Examples of the monomer which is copolymerizable with MVC and the homopolymer of which has a glass transition temperature below 30C include olefins such as ethylene and propylene, vinylidene halides such as vinylidene chloride, vinyl esters ~uch as vinyl acetate, vinyl ethers such as n-butyl vinyl ether, acrylic acid ester~ such as butyl acrylate and 2-ethylhQxyl acrylate, and methacrylic acid esters such as 2-ethylhexyl methacrylate.
The amount of the above monomer contained in the MVC-based monomer is preferably 50% by weight or less, more preferably 30% by weight or less. This i~ because if the amount thereof exceeds S0~ by weight, the resulting -- . 1 1 --,~

urethane-vinyl chloride type copolymer is poor in processability, moldability and heat resistance.
!The polymerization for producing the urethane- vinyl ichloride type copolymer to be employed in thi~ invention may be performed by either the suspension polymerization method or the emulsion polymerization method. Por ~uspension polymerization, a known suspension stabilizer may be used.
Examples thereof include partly saponified poly(vinyl alcohol), methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, poly(acrylic acid), vinyl ether-maleic anhydride copolymers and gelstin. These may be used alone or in combination.
The amount of such suspension stabilizer( 9 ) used generally ranges from 0.01 to 2 wt~ based on the amount of the agueous reaction medium.
A known oil-soluble polymerization initiator may be used for the polymerization for producing the urethane-vinyl chloride type copolymer. Examples of such initiator~ include azo compounds such as azobisisobutylvaleronitrile and organic peroxides such as lauryl peroxide, di-2-ethylhexyl peroxydicarbonate, and t-butyl peroxypivalate. The amount of the polymerization initiator used is generally from about 0.01 to 2 wt% based on the amount of the MVC-based monomer introduced.
It is preferable, in performing the polymerization for producing the urethane-vinyl chloride copolymer, that the ratio .
:

- 20~9931 of the amount of the agueous reaction medium used to the total introduced amount of the MVC-soluble TPU and the MVC-ba~ed monomer be in the range of from 1/1 to 3/1 by weight. This is because if the ratio is lower than 1/1, the polymerization proceeds in an unstable manner, and if the ratio i~ higher than 3/1, the process becomes economically disadvantageous.
The polymerization temperature is generally between 30 to 70C, preferably between 40 to 60C. This is because temperatures below 30C are industrially disadvantageous since the polymerization rate is prone to be low, while temperatures higher than 70C are also non-preferred in that the resulting polymer i~ apt to be poor in heat resi~tance and other properties.
In conducting the polymerization described above, a known chain transfer aqent such as trichloroethylene, mercaptoethanol or the like may be used.
The Calcium Carbonate The calcium carbonate to be mixed as a filler with the urethane-vinyl chloride type copolymer described above is not particularly limited in kind, and any of the calcium carbonat-s generally incorporated as a filler in various synthetic resins may be employed. However, the average particle diameter of the calcium carbonate is preferably from 0.015 to 100 ~m, more preferably from 0.1 to 10 ~m, because the ~ .
, 2~Q9931 development of fisheye~ and the properties of the final molded articles are affected by the particle size of the filler.
lf the average particle diameter of the calcium carbonate is less than 0.015 ~m, agglomerates of calcium carbonate are apt to be formed during kneading, often resulting in fisheyes on the surfaces of final molded articles. On the other hand, if the average particle diameter thereof exceeds 100 ~m, the final molded articles will be prone to be poor in surface smoothness and also in physical strength.
Of the above mentioned calcium carbonates, ones which have been surface treated with an organic compound such as those now given are particularly preferably employed in this invention, because such calcium carbonate~ ~how excellent dispersibility and, hence, agglomeration thereof does not occur And they can be more uniformly mixed with the urethane-vinyl chloride type copolymer by kneadinq.
Examples of surface-treating agents for the calcium carbonate include higher fatty acids such as stearic acid, palmitic acid, and myristic acid; metal salts of such fatty acids; higher fatty acid amides such as stearylamide and methylene-bis-stearylamide; organotitanium compounds such as isopropyl triisostearoyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate; silane coupling agent~ such as y-aminopropyltriethoxy~ilane; and paraffins or polyethylene waxes. Surface treatment of calcium carbonate with such an ;j," i' 20~9931 organic compound can be effected by a method (~lurry method) ln which the organic compound is added to a 15 wt% aqueous slurry of calcium carbonate in an amount of about 0.1 to 2 parts by weight per 100 parts by weight of the calcium carbonate, the resulting ~lurry is stirred, and then the calcium carbonate i8 dehydrated and dried, or a method in which the organic compound is added to dry calcium carbonate which has been dried at 100 to 150C for 3 to 4 hours, in an amount substantially the same a~i that in the above method, and the resulting calcium carbonate is stirred with a mixer or the like at room temperature to 170C for several minutes to 1 hour.
The amount of the calcium carbonate contained in the resin compo~ition of this invention is preferably from 5 to 100 parts by weight, more preferably from 20 to 60 parts by weight, per 100 parts by weight of the urethane-vinyl chloride type copolymer described hereinbefore. If the amount of the calcium carbonate is below 5 parts by weight, the calcium carbonate cannot fully exhibit, during the kneading with the urethane-vinyl chloride type copolymer, the effect of di~inishing fisheyes contained in the copolymer. On the other hand, if the amount thereof exceeds 100 parts by weight, molded articles obtained from the resulting resin composition are prone to be low in physical strength.

~ 20~9931 The Heat Stabilizer Although the moldable resin composition of this invention, in which a heat stabilizer and calcium carbonate have been incorporated, is required to have a 200C heat stability of 60 minutes or more as measured in accordance with JIS R 6723 ~1983), use of highly effective heat stabilizers such as lead- or tin-containing stabilizers that are used for other chlorine-containing polymers such as poly~vinyl chloride) is not preferred in this invention since such stabilizers act as a hydrolysis catalyst for urethane bonds in the urethane-vinyl chloride copolymer.
Besides the epoxy heat stabilizers mentioned hereLnbefore, which are generally used for vinyl chloride resins, e~emplary heat stabilizers preferably employed in this invention include epoxy resins, metal salts of organic acids, metal salts of 8ilicic acid, hydrotalcites, metal oxides, organic phosphites, polyols, ~-diketo compounds, aminocarboxylic acids, sulfur-containing compounds, and salts of halogenooxyacids. These stabilizers are preferably used as a combination of two or more thereof. The amount of the heat stabilizer incorporated in relation to the urethane-vinyl chloride type copolymer varies depending upon the kind of the heat stabilizer, but it should be sufficient to impart heat stability at 200C of 60 minute~ or more to the urethane-vinyl chloride type copolymer in which calcium carbonate has been I -20~19931 incorporated. The amount of the heat stabilizer i~ preferably 8 parts by weight or less, more preferably 5 part~ by weight or less, per 100 parts by weight of the urethane-vinyl chloride type copolymer, since too large an amount thereof results in blooming and causes the mechanical strength of final molded articles to be low.
Representative examples of the various kinds of heat stabilizer compounds as mentioned above are given below.
Epoxy re~ins include bisphenol epoxy resins such a~
Araldite 502 (manufactured by Ciba-Geigy Limited; epoxy equivalent 233-250 (hereafter, numerical values given for ~ueh resins are all epoxy equivalants))~ Araldite 508 (Ciba-Geigy;
400-455), Epiclon 850 (Dainippon Ink & Chemicals, Inc., Japan;
184-194), Epiclon 830 (Dainippon Ink ~ Chemieals; 170-190), Epicote 828 (Shell Chemical Co.; 184-194), Epicote 834 (Shell Chemical; 230-270), Sumiepoxy eLA 128 (Sumitomo Chemical Co., ~td., Japan; 184-194), and EP-4100 (Asahi Denka ~ogyo R.K., Japan; 180-200); and epoxy novolac resins sueh as DEN 431 (manufactured by The Dow Chemical Co.; 172-179), DEN 438 (Dow Chemical; 175-182~, Epiclon N-740 (Dainippon Ink & Chemicals;
170-190), Epiclon N-680 (Dainippon Ink & Chemicals; 220-240), CIBAEPN 1139 (Ciba-Geigy; 172-179), and CIBAECN 1273 (Ciba-Geigy; about 225).
Metal salts of organic acids include those in which the organic acid moieties derive from caproic acid, myristic acid, .

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20~9931 palmitic acid, undecylenic acid, ricinoleic acid, linolic acid, oleic acid, stearic acid, isostearic acid, 12-hydroxystearic acid, chlorostearic acid, phenylstearic acid, arachic acid, coconut oil fatty acid, tung oil fatty acid, soybean oil fatty acid, benzoic acid, chlorobenzoic acid, toluic acid, salicylic acid, p-tert-butylbenzoic acid, 5-tert-octylsalicylic acid, naphthenic acid, xylylic acid, ethylbenzoic acid, isopropylbenzoic acid, di-tert-butylbenzoic acid, bromobenzoic acid, monobutyl maleate, monodecyl phthalate, cyclohexanecarboxylic acid, a phenol, or the like, and in which the metal~ are a Group IIb metal of the periodic table such as zinc, cadmium, etc., a Group Ia metal f3uch as lithium, isodium, potassium, etc., or a Group IIa metal ~3uch a~ barium, calcium, magne~ium, istrontium, etc.
Metal salts of ~ilicic acid include calcium silicate, bairium silicate, zinc silicate, magnesium silicate, and strontium silicate.
Hydrotalcite~ preferably employed in this invention are those represented by formula (I) M2~l~M3~(oH)2An-~/~ mH20 (I) wherein N2~ is a divalent ion of a metal such as Ng, Ca, Sr, Ba, Zn, Cd, Sn, Pb, Ni, etc., N3' is a trivalent ion of a metal such as Al, In, B, Bi, etc., A~- is an anion having a valency (n) of 1 to 4, . ' ' ',~
, .

J 20~9931 X i8 O~X<O . 5 ~ and m is O~m<2.
Of these, the hydrotalcite represented by formula (~I) given below is being sold by Kyowa Chemical Industry Co., Ltd., Japan under the trade name of DH~r-4A, and it may be used as it is.
NgO.~Al0.3(0H)2(C03)o.l~ 0-54H20 (II) Metal oxides include magnesium oxide, zinc oxide, calcium oxide, barium oxide, and strontium oxide.
Organic phosphites include diphenyl decyl phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tributyl phosphite, tri~(dinonylphenyl) phosphite, trilauryl trithiophosphite, trilauryl phosphite, and tetratridecyl 4,4-n-butylidenebis(2-tert- butyl-5-methylphenol) diphosphite.
Polyols include glycerin, diglycerol, sorbitol, mannitol, xylitol, pentaerythritol, dipentaerythritol, trimethylolpropane, poly(ethylene glycol), and poly(vinyl alcohol).
B-Diketo compounds include ethyl acetoacetate, calcium ethylacetoacetate, benzoylacetic acid esters, dehydroacetic acid, acetylacetone, benzoylacetone, dibenzoylmethane, and stearoylbenzoylmethane.
Aminocarboxylic acids include dibutyl aminocrotonate, 1,2-dipropylene glycol ester of aminocrotonic acid, thiodiethylene glycol ester of aminocrotonic acid, _ ,9 _ ;~ ' '- " '~- . ' , ' ' ' ".' .''., ', . ' , ' ' "' . . ' . ' , ' 201~9931 acetylmethionine, acetyllysine, acetylphenylalanine, and acetylglutamic acid.
Sulfur-containing compounds include dilauryl thiopropionate, distearyl thiopropionate, lauryl stearyl thiodipropionate, dimyristyl thiodipropionate, 6-anilino-1,3,5-triazine-2,4-dithiol, 6-dibutylamino-1,3,5-triazine-2,4-dithiol, and thiollauric anhydride.
Further, salts of halogenooxyacids include, for example, ~alts (Zn, Al, NH~, Cd, R, Ca, Sr, Na, Pb, Ba, Mg, ~i) of perchloric acid; salt~ (Zn, NH~, R, Na, Pb, Ba, Li) of periodic acid; salts (Zn, Al, NH~, Cd, R, Ca, Sr, Na, Pb, Ba, Mg, Li) of perbromic acid; salts (Zn, Al, NH~, Cd, R, Ca, Sr, Na, Pb, Ba, Ng, ~i) of chloric acid; salts (Zn, Al, NH~, Cd, R, Ca, Sr, Na, Pb, Ba, Mg, Li) of bromic acid; ~aIts (Zn, Al, NH~, Cd, R, Ca, Sr, Na, Pb, Ba, Mg, Li) of iodic acid; ~alts (Zn, Cd, R, Na, Pb, Ca, Ba) of chlorou~ acid; salt~ (Li, Na, R, Ca, Sr, Ba, NH~) of hypochlorous acid; and ~alts (Na, ~, Ca, Ba) of bromou~ acid. The~e may, of course, be salt~ in the hydrated form.
Of the above-mentioned heat stabilizer compounds, a heat stabilizer comprising an organic acid salt and a hydrotalcite in a weight ratio of from 2~1 to 1/1, and a heat stabilizer compriaing an organic acid salt and a halogenooxyacid salt in a weight ratio of from 4/1 to 1/1 are particularly effective in imparting the above-mentioned heat '' . ..
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- 20~9931 stability, i.e., 60 minutes or more in terms of 200C heat stability as measured in accordance with the msthod provided for in JIS R 6723 (1983), to the urethane-vinyl chloride type copolymer when incorporated in an amount within the preferred upper limit as mentioned hereinbefore, i.e., 8 part6 by weight or less per 100 parts by weight of the copolymer, or more preferably in an amount not larger than 5 parts by weight. In the case where the former stabilizer system is employed, the required heat stability can be imparted to the urethane-vinyl chloride type oopolymer by adding the stabilizer in an amount of 3 to 5 parts by weight per 100 parts by weight of the copolymer. In the case of the latter stabilizer system, the required heat stability can be obtained when the incorporated stabilizer ~ystem amount i8 2 to 5 parts by weight per 100 parts by weight of the urethane-vinyl chloride type copolymer.
Preferred moldable resin compositions of this invention are ones having a 200C heat stability of 100 minutes or more as measured by the above specified method. For imparting such heat stability, a heat stabilizer consisting essentially of an organic acid metal salt, a hydrotalcite, and a halogenooxyacid salt is preferably employed. Specifically, such a heat stabilizer system is one which contains an organic acid metal salt and a hydrotalcite with the proportion of the former to the latter being from 85/15 to 75/25 by weight, and which further contains 20 to 50% by weight of a halogenooxyacid salt ,;' ', ' ' ' .':,, ~ ' '',' " ' , ':: ,., ': :.: ~ ,'. '' ', ,''' . '; ~', : :, '., ' :, :. ' based on the total amount of the all components of the heat -stabilizer system. The 3-component heat stabilizer is added in an amount of 2 to 5 parts by weight per 100 parts by weight of the urethane-vinyl chloride type copolymer.
With stabilizers other than the 3-component heat stabilizer system described above, it is difficult to obtain moldable resin compositions having a 200C heat stability of 100 minutes or more.
The method for determining heat stability as provided for in JIS R 6723 includes the following procedures. A sample is cut into pieces each ~ide of which i9 not more than 1 mm, and 2 g of the sample pieces are placed into a test tube. A
Congo Red test paper (7mm x 40mm) wetted with glycerin is hung down in the te~t tube. The re~ulting test tube is immersed vertically in an oil bath kept at 200 + 3C, and the time nece~sary for the end of the test paper to turn blue is mea~ured.
Rneadina The moldable resin composition of thi~ invention can be produced by sufficiently kneading the above described urethane-vinyl chloride type copolymer, calcium carbonate and heat stabilizer at a temperature of usually 160 to 180C by a conveutroural method, to thereby decrease fisheyes contained in the urethane-vinyl chloride type copolymer to an extremely low amount. If needed, the resulting composition is, for - 22 - ;
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example, formed into pellets to give a pelletized resin composition for use in shaping.
Apparatus which can be used for the kneading of the above described ingredients include mixing rolls, Banbury mixers, full flighted single screw extruders, barrier screw extruders, and Werner type twin screw extruders. Preferred of these are extruders with a screw provided with a barrier mechanism, such as barrier flights, so as to reduce the clearance from the cylinder, i.e., to form a barrier, thereby to prevent coarse particles from passing therethrough (such extruders being hereafter referred to as extruders with a barr1er screw).
As such extruders with a barrier screw, there may be mentioned fluted mixing screw extruders and Dulmage screw extruder~, besides the above mentioned barrier flight screw extruder~. Any of these types can be employed in this invention, but those having barrier clearances of 0.5 mm or les~ are preferred.
If the clearance exceedis 0.5 mm, there are cases where relatively coarse agglomerates of calcium carbonate contained in the resin composition pass, as they are, through the extruder along with thé resin, and this often impairs the surface appearance of final molded articles obtained from the thus extruded resin composition.

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~!i : i :: i . , :: ~ .- . , :- -20~9931 The barrier screw preferably employed in the kneading for producing the re~in composition of this invention preferably has an L/D (effective screw length/screw diameter) ratio of from 10/1 to 50/1, with a more preferred ratio being from 20/1 to 40/1.
If the L/D ratio i8 below 10/1, the result i~
insufficient kneading because of too ~hort a residence time for the resin composition. If L/D exceeds 50/1, the resin composition disadvantageously undergoes heat deterioration because its re~idence time becomes too long.
Specific examples of extruders with a barrier ~icrew include the BM screw extruder manufactured by the Maillefer Company, the Plastiscrew extNder and the ~M screw extruder both manufactured by Mitsubish Heavy Industrie~, Ltd., Japan, the Fluted mixing device extruder manufactured by the Union ~ I
Carbide Corp., the Unimelt screw extruder manuf~ctured by Toshiba Machine Co., ~td., Japan, the DIS screw extruder manufactured by Plastic Rogaku Renkyu~o R.R. Japan, and the vent extruders manufactured by Ishinaka Tekko~o R.R., Japan.
In addition to the urethane-vinyl chloride type -, ~ . .
copolymer, heat stabilizer and calcium carbonate, the resin composition of the present invention may contain, according to ~-;
need, a flame retardant, lubricant, antioxidant, colorant, processing aid, light stabilizer, ultraviolet absorber, foaming agent, and the like.

_ 24 -20~9931 The resin composition of this invention can be shaped into various kinds of molded by methods generally employed in the field of poly(vinyl chloride) processing, for example by extrusion or in~ection molding at a molding temperature of, for example, 170 to 180C. For example, it is well suited for use in the production of decorative or protective parts for automoble including side moldings, tubes and hoses, various kinds of sheets such as waterprof sheet, sheet for tents, sheets for waterproofing rooftop~, leather-like sheets, soundproofing ~heets, wire coatings, gaskets for w$ndow frames, and packings for vehicles.
From the moldable resin composition according to the present invention, there can be obtained molded articles containing very few fisheyes and which have a smooth and beautiful surface, as compared with molded articles obtained form conventional urethane-vinyl chloride copolymer-base resin compositions for use in shaping. Furthermore, since the compositio;~ of this invention is also excellent in heat stability, the composition is advantageous in that it can be ea~ily sub~ected to in~ection molding and enables excellent long term running properties.
The present invention will be explained below in more detail by reference to Examples and Comparative Examples, in which all parts are by weight.

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20~9931 Into a stainless-steel autoclave having a capacity of liters were introduced 45 parts of a thermoplastic polyurethane elastomer (Pandex T-5265, manufactured by Dainippon Ink & Chemicals, Incorporated; a polyurethane composed mainly of an adipate and an aliphatic diisocyanate and having softening point of 53C, 20% MER viscosity of 800 cp~
and a molecular weight of 119,782), 3 parts of epoxidized soybean oil (oxirane oxygen content: 6.9 wt%), 200 parts of pure water, 0.8 part of partly saponified poly(vinyl alcohol) (Gohsenol RH-17, manufactured by The Nippon Synthetic Chemical Industry C0., ~td., Japan), and 0.08 part of di-2-ethylhexyl peroxydicarbonate. The air in the autoclave was replaced w$th nitrogen and then 55 parts of monomeric vinyl chloride was fed to the autoclave. Reaction was allowed to proceed at 51C for 15 hours. Subsequently, the monomer remaining unreacted was removed, and the reaction product was separated from the water and dried, thereby obtaining 90 parts of a polymer in the form of powder.
The urethane-vinyl chloride type copolymer thus obtained was blended with the various ingredients shown in Table 1 below. The resulting blend was granulated and then formed into a sheet 1 mm in thickness by mean~ of a 40D full flighted sinqle screw extruder at 170C. The thus-obtained sheet was evaluated for heat stability, hardness, tensile - .

_ 26 -~ .,, ' .

- 20~9931 strength and surface appearance. The results obtained are summarized in Table 1.
The heat stability values in the table are expressed in terms of 200C heat stability as measured in accordance with the method provided for in JIS R 6723 (1983), while the hardness and tensile strength values were obtained in accordance with JIS R 6301.

A shee~ for property evaluation was prepared in the same manner a8 in Example 1 except that a 40D fluted mixing-screw ext Nder was used as a kneading machine in place of the 40D full flighted single screw ext Nder used in Examples 1 and 2. The sheet obtained was evaluated for the same properties as in Examples 1 and 2. The results obtained are hown in Table 1.
: COMPARATIVE EXAMPLE 1 A urethane-vinyl chloride type copolymer was produced in the same manner as in ~xample 1 except that polymerization ~ wasi carried out without adding the epoxy stabilizer. The : thus-obtained urethane-vinyl chloride type copolymer was blended with the heat stabilizers and calcium carbonate as shown in Table 1, and the resulting blend was formed into a sheet for property evaluation through kneading and ext N sion ¦;~ which were conducted under the same conditions as in Example 1.

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20~9931 Properties of the sheet thus obtained were evaluated, and the re~ults obtained are ~hown in Table 1.

Sheets for property evaluation were prepared in the same msnner as in Example 1 except that the heat stabilizers shown in Table 1 were u~ed, and properties of the sheets were evaluated. The resultis obtained are ~hown in Table 1.

Sheets for property evaluation were prepared in the same manner a~ in Example 1 except thi~t in place of the calcium carbonate used in ~xample 1, talc (Comparative Example 4) or silica (Comparative Example 5) wa~ u~ed a~ an inorganic filler.
Propertie~ of the sheets were evaluated, and the results obtaLned are shown ln Table 1.

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` 20Q9931 While the invention has been de~cribed in detail and with reference to specific embodiment~ thereof, it will be apparent to one skilled in the art that variou~ changes and modification~ can be made therein without departing from the spirit and ~cope thereof.

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Claims

1. A moldable resin composition having a 200°C heat stability of 60 minutes or more, which comprises a polymer, calcium carbonate and a heat stabilizer, said polymer being produced by polymerizing (i) monomeric vinyl chloride or (ii) a monomer mixture composed of (a) monomeric vinyl chloride and (b) a monomer which is copolymerizable therewith and which yields a homopolymer having a glass transition temperature below 30°C, in the presence of 10 to 200 parts by weight, per 100 parts by weight of said monomeric vinyl chloride (i) or said monomer mixture (ii), of a thermoplastic polyurethane elastomer which is soluble in monomeric vinyl chloride at the polymerization condition and has a softening point in the range of from 20 to 100°C.

2. The moldable resin composition as in claim 1, wherein said polymerizing is further conducted in the presences of an epoxy heat stabilizer in an amount of 30 parts by weight or less per 100 parts by weight of the monomeric vinyl chloride or the monomer mixture.

3. The moldable resin composition as in claim 1, wherein said thermoplastic polyurethane elastomer has a solution viscosity of 30 to 1000 cps as a 20 wt% solution in methyl ethyl ketone.

4. The moldable resin composition as in claim 1, wherein the content of the thermoplastic polyurethane elastomer in said polymer is 10 to 80 wt%.

5. The moldable resin composition as in claim 1, wherein said monomer mixture comprises 50 wt% or less of the monomer (b).

6. The moldable resin composition as in claim 1, wherein said calcium carbonate has an average particle diameter of 0.015 to 100 µm and is used in an amount of from 5 to 100 parts by weight per 100 parts by weight of said polymer.

7. The moldable resin composition as in claim 6, wherein said calcium carbonate has been surface treated with an organic compound to increase the dispersibility thereof in said polymer as compared to the corresponding untreated calcium carbonate.

8. The moldable resin composition as in claim 1, wherein said heat stabilizer is used in an amount of 8 parts by weight or less per 100 parts by weight of said polymer.

9. The moldable resin composition as in claim 2, wherein said epoxy heat stabilizer is selected form the group consisting of an epoxidized vegetable oil, an epoxidized animal oil, an epoxidized ester of an aliphatic carboxcyclic acid, an epoxidized diester of an aliphatic carboxcyclic acid, an alicyclic epoxide, epoxy stearyl benzoate and methyl epoxy stearyl phthalate.

10. The moldable resin composition as in claim 1, wherein said heat stabilizer is at least one of the compounds selected from the group consisting of epoxy heat stabilizers, epoxy resins, metal salts of organic acids, metal salts of silicic acid, hydrotalcites, metal oxides, organic phosphites, polyols, .beta.-diketo compounds, aminocarboxylic acids, sulfur-containing compounds, and salts of halogenooxyacids.

11. The moldable resin composition as in claim 10, wherein said heat stabilizer comprises an organic acid salt and a hydrotalcite in a weight ratio of from 2/1 to 1/1.

12. The moldable resin composition as in claim 11, wherein said heat stabilizer is used in an amount of from 3 to 5 parts by weight per 100 parts by weight of said polymer.

13. The moldable resin composition as in claim 10, wherein said heat stabilizer comprises an organic acid salt and a halogenooxyacid salt in a weight ratio of from 4/1 to 1/1.

14. The moldable resin composition as in claim 13, wherein said heat stabilizer is used in an amount of from 2 to 5 parts by weight per 100 parts by weight of said polymer.

15. The moldable resin composition as in claim 10, wherein said heat stabilizer consists essentially of an organic acid salt, a hydrotalcite and a halogenooxyacid salt, and the weight ratio of the organic acid salt to the hydrotalcite is from 85/15 to 75/25 and the content of the halogenooxyacid salt is 20 to 50 wt% based on the total amount of the heat stabilizer.

16. The moldable resin composition as in claim 15, wherein said heat stabilizer is used in an amount of from 2 to S parts by weight per 100 parts by weight of said polymer.

17. The moldable resin composition as in claim 1, which is subjected to kneading using an extruder with a barrier screw.

18. The moldable resin composition as in claim 17, wherein said extruder has a barrier clearance of 0.5 mm or less.

19. The moldable resin composition as in claim 17, wherein said barrier screw has an effective screw length/screw diameter ratio of from 10/1 to 50/1/

20. The moldable resin composition as in claim 1, which has a 200°C heat stability of 100 minutes or more.