AU620070B2 - Water service pipe and additive for production thereof - Google Patents

Description

AUSTRALIA

Patents Act COM1PLETE SPECIFICATION~

(ORIGINAL)

620070O Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priori ty Related Art: APPLICANT'S REFERENCE: 6351 MK 0 Name(s) of Applicant(s): Mizusatwa Industrial Chemicals, Ltd *Address(es) of Applicant(s): 1-21, muromachi 4 chome, Nihonbaslhi, Chuo-ku, Tokyo,

JAPAN.

Al' Address for Service is: PHILLIPS 0RD1GNDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: WATER SERVICE PIPE AND ADDITIVE FOI' PR~ODUCTIONI TL1EREOF Our Ref :121708 POF Code: 1523/62630 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6003q/1- I

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'1 k 4 la- WATER SERVICE PIPE AND ADDITIVE FOR PRODUCTION THEREOF Background of the Invention Field of the Invention The present invention relates to a water service pipe composed of a chlorine-containing polymer composition and also to an additive for use in the production thereof. More particularly, the present invention relates to a water service pipe in which elusion of lead is controlled and also to an additive for use in the production thereof.

Description of the Related Art A chlorine-containing polymer, for example, a vinyl 15 chloride resin, undergoes dehydrochlorination in the ,I molecule chain when exposed to heat or light, resulting in decomposition, discoloration and deterioration. The decomposition reaction by dehydrochlorination is a selfcatalytic reaction in which formed hydrogen chloride S, O 20 acts as a catalyst. Accordingly, various stabilizers or stabilizer compositions for catching this hydrogen t: chloride and heat-stabilizing the vinyl chloride resin have been proposed.

As the heat stabilizer for pipes, a lead salt of a 25 fatty acid and a tribasic lead salt have been used, and it is known that these lead type stabilizers are especially excellent in the heat-stabilizing effect.

However, a vinyl chloride resin pipe in which such a lead type stabilizer is incorporated involves a problem in that lead is dissolved out in water at a concentration of scores of ppb to several hundred ppb at the start of the use.

We previously proposed in Japanese Patent Publication No. 0B939/83 that a zeolite of the type A, optionally with a lead salt of a fatty acid, a basic lead salt or other inorganic stabilizer, is incorporated into a chlorine-containing polymer. Furthermore, in Japanese Patent Application Laid-Open Specification No.

142o043/83, it is taught that if a zeolite of the type A and a lead type stabilizer are incorporated in a vinyl chloride resin, elusion of lead is controlled.

In the production of molded articles such as pipes, a filler is ordinarily incorporated in a resin composition for attaining a bulking effect, improving the moldability and adjusting the st' -ngth or hardness.

In the production of a pipe of a chlorine-containing polymer, a calcium carbonate filler is most prc'terred in view of the dispersibility in the resin, the auxiliary 0 0 stabilizing effect and the price.

o4 c15 However, it was found that if a calcium carbonate filler is incorporated together with a lead type stabilizer such as a lead salt of a fatty acid or a basic lead salt into a chlorine-containing polymer, elusion of 0 lead from a formed service water pipe is much larger 00 0 o o0 20 than in case of a calcium carbonate-free pipe.

Summary of the Invention 0 o stabIt is therefore a primary object of the present invention to effectively control elusion of lead in a water service pipe composed of a chlorine-containing 25 polymer composition in which a lead type stabilizer and o 0* a calcium carbonate filler are incorporated.

Another object of the present invention is to provide a water service pipe of a chlorine-containing 2 polymer which has a controlled elusion quantity of lead, an excellent heat stability, a high strength and an excellent appearance in combination.

In accordance with one aspect of the present invention, there is provided a water service pipe which is composed of a resin composition comprising 100 parts by weight of a chlorine-containing polymer, 0.1 to

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3 t I 00 0 i 4' 0 44 Il 0 0 4 I *I4 44 4 6O 4 0 I 0li I *I 0I parts by weight of a lead type stabilizer comprising a lead salt of a fatty acid, a combination of a lead salt of a fatty acid and a basic lead salt, a combination of a lead salt of a fatty acid and a tin type stabilizer or a combination of a lead salt of a fatty acid and a metal soap type stabilizer, 0.01 to 15 parts by weight of a calcium carbonate filler, up to 5.0 parts by weight of a lubricant and 0.01 to 3.0 parts by weight of a zeolite of the type A.

It is preferred that in the zeolite of the type A used in the present invention, the hydrogen chloride capture quantity defined as the quantity of hydrochloric acid necessary for reducing the pH value of the zeolite to 5 from 9 by using a 0.4N aqueous solution 15 of hydrochloric acid be at least 3 m//g.

In accordance with another aspect of the present invention, there is provided a one-package additive for a chlorine-containing polymer, which comprises a lead type stabilizer comprising a lead salt of a fatty acid, 20 a combination of a lead salt of a fatty acid and a basic lead salt, a combination of a lead salt of a fatty acid and a tin type stabilizer or a combination of a lead salt of a fatty acid and a metal soap type stabilizer, (ii) a calcium carbonate filler, (iii) a lubricant and (iv) a zeolite of the type A, said components (i) through (iv) being mixed so that the amounts of the components through (iv) are 0.1 to 5 parts by weight, 0.01 to 15 parts by weight, up to 5 parts by weight and 0.01 to 3 parts by weight, respectively, per 100 parts by weight of the chlorine-containing polymer.

In accordance with still another aspect of the present invention, there is provided a stabilizer fonr a chlorine-containing polymer, which comprises sodium aluminosilicate or calcium aluminosilicate having an Xray diffraction pattern inherent to a zeolite of the tI 0 II I 19 1 i type A or a mixture thereof, wherein the hydrogen chloride capture quantity defined as the quantity of hydrochloric acid necessary for reducing the pH value of the zeolite to 5 from 9 by using a 0.4N aqueous solution of hydrochloric acid is at least 3 the maximum reduction gradient (Rmax) determined from the tangential line of the maximum gradient portion of the hydrochloric acid titration curve is -0.1 to -0.7 pH/meq HC. per 100 g of the zeolite, and the maintenance pH reduction gradient (Rmain) determined from the tangential line of the subsequent small-inclination portion of the hydrochloric acid titration curve is -0.001 to -0.07 pH/meq HCi per 100 g of the zeolite.

Brief Descriotion of the Drawings 'a o4 a 44 *4 *r 4 4 4.

44 a,+ a 4a Fig. 1 is a diagram illustrating the elusion quantity of lead from a water service pipe composed of rigid polyvinyl chloride containing, incorporated therein, a lead type stabilizer and calcium carbonate, in which a zeolite of the type A is incorporated or not 20 incorporated. In Fig. 1, A-i illustrates the results of Runs 2, 15, 16 and 17 according to the present invention, A-2 illustrates the results of Runs 18, 19, and 21 according to the present invention, B-1 illustrates Runs 26, 27, 28 and 29 as comparative runs, and B-2 illustrates the results of runs 30, 31, 32 and 33 as comparative runs.

Fig. 2 shows a hydrochloric acid titration curve of an aqueous dispersion of the zeolite of the type A used in the present invention. In Fig. 2, C-1, C-2, C-3, C-4 and 0-5 are curves of zeolite A samples NA-21, NA-11, CA- 12, CA-22 and CA-23 obtained in Examples 1 and 2.

Detailed Description of the Invention The present invention is based on the novel finding that if a zeolite is incorporated in a chlorinecontaining polymer composition containing a lead type 1 5 09 o 9 9a 49 9 4 9s 6 stabilizer and a calcium carbonate filler, elusion of lead from a pipe formed of this composition is prominently controlled.

Curve B in Fig. 1 of the accompanying drawings shows the relation between the amount incorporated of calcium carbonate and the initial elusion quantity of lead from a pipe formed of a composition comprising 100 parts by weight of a vinyl chloride resin, 1.8 parts by weight of a lead type stabilizer (lead stearate) and a variable amount of calcium carbonate. From the results of curve B of Fig. 1, it is seen that with increase of the quantity of calcium carbonate incorporated as the filler, the initial elusion quantity of lead from the pipe drastically increases.

On the other hand, curve A in Fig. 1 shows the relation between the amount incorporated of calcium carbonate and the initial elusion quantity of lead from a pipe formed of the above composition in which a zeolite A of the Na type (Mizukariser DS) is further incorporated in an amount of 0.5 part by weight. If curve A is compared with curve B in Fig. 1, it is understood that by incorporating a zeolite of the type A, even if the amount incorporated of calcium carbonate is increased, the elusion quantity of lead from the pipe is controlled to a very low level.

The reasons why the elusion quantity of lead increases with increase of calcium carbonate in th.

composition of the above-mentioned system and the elusion quantity of lead is controlled to a low level even in case of incorporation of calcium carbonate by addition of a zeolite of the type A have not sufficiently been elucidated. However, we presume that the reasons will probably be as follows.

It is believed that elusion of lead from the pipe is not elusion of the used lead type stabilizer per se I -I -6but is elusion of lead chloride formed by reaction with hydrogen chloride formed by the decomposition of the chlorine-containing polymer. In a chlorine-containing polymer in which calcium carbonate and a lead type stabilizer are incorporated, calcium chloride is formed at the melt-molding step. Since calcium chloride has a strong water-absorbing property, it is believed that lead chloride simultaneously formed by this reaction or lead chloride formed by ion exchange with calcium chloride is dissolved out from the surface of the pipe.

In the case where a zeolite of the type A is incorporated, reaction between hydrogen chloride and the 000* zeolite A is preferentially advanced while reaction between calcium carbonate and hydrogen chloride is 6 0, 15 inhibited, and therefore, formation of calcium chloride S0 having a high water-absorbing property is controlled, 0 with the result that elusion of lead is drastically reduced.

From the foregoing viewpoint, it is preferred that the above-mentioned hydrogen chloride capture quantity of the zeolite A used in the present invention be at tol least 3 especially 5 to 10 mA/g.

Incidentally, the hydrogen chloride capture quantity is defined as the quantity of hydrochloric acid necessary for reducing the pH value to 5 from 9 in the present invention. The reason is that it is considered that this pH range is effective for the actual capture of hydrogen chloride, the enhancement of the heat stability and the control of the elusion of lead.

More specifically, if the pH value is higher than 9, the zeolite A tends to cause initial coloration of the chlorine-containing polymer, and if the pH value is lower than 5, the capture of hydrogen chloride is not preferentially effected. Therefore, it is construed that the above-mentioned pH range is preferred for 1

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A 7 a It 4r Ie C 4 4 44 4) 41 I *I 44 4) 4, 444*4 defining the zeolite A.

As the chlorine-containing polymer, there can be optionally used known chlorine-containing resins, for example, polyvinyl chloride, vinyl chloride copolymers such as a vinyl chloride/vinyl acetate copolymer, a vinyl chloride/ethylene copolymer, a vinyl chloride/propylene copolymer, a vinyl chloride/styrene copolymer, a vinyl chloride/isobutylene copolymer, a vinyl chloride/vinylidene chloride copolymer, a vinyl chloride/styrene/maleic anhydride copolymer, a vinyl chloride/styrene/acrylonitrile copolymer, a vinyl chloride/butadiene copolymer, a vinyl chloride/icoprene copolymer, a vinyl chloride/chlorinated propylene copolymer, a vinyl chloride/vinylidene chloride/vinyl 15 acetate copolymer, a vinyl chloride/acrylic acid ester copolymer, a vinyl chloride/maleic acid ester copolymer and a vinyl chloride/methacrylic acid ester copolymer, vinylidene chloride resins, chlorinated polyethylene, chlorinated polyvinyl chloride, chloropren rubber, and 20 chlorinated polychloroprene. Furthermore, there can be used blends of these chlorine-containing resins with o(olefin polymers such as polyethylene, polypropylene, polybutene and poly -3-methylbutene, polyolefins such as an ethylene/vinyl acetate copolymer and an 25 ethylene/propylene copolymer, copolymers thereof, polystyrene, acrylic resins, copolymers of styrene with other monomers (for example, maleic anhydride butadiene and acrylonitrile), an acrylonitrile/butadiene/styrene copolymer, an acrylic acid ester/butadiene/styrene copolymer and a methacrylic acid ester/butadiene/styrene copolymer, and chlorine-containing rubbers.

The lead type stabilizer is an indispensable component for imparting a high heat stability required for a water service pipe. As the lead type stabilizer, there can be used a lead salt of a fatty acid, a

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i 4t 4

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441 1 I :1 4 tI 4 4I1 yi

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5 1 10 i

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~I 8 combination of a lead salt of a fatty acid, a combination of a lead salt of a fatty acid and a tin type stabilizer, and a combination of a lead salt of a fatty acid and a metal soap type stabilizer. The lead salt of the fatty acid exerts not only a heat stabilizing action but also a lubricating action and is able to increase the effective lead content to a relatively high level while maintaining a good balance among functions of the respective ingredients. Therefore, the lead salt of the fatty acid is used as the lead type stabilizer in the present invention.

As the lead salt of the fatty acid, there can be mentioned lead salts of higher fatty acids, especially saturated and unsaturated fatty acids having 8 to 22 carbon atoms, such as lauric acid, palmitic acid, stearic acid, octadeconoic acid, oleic acid, linoleic acid and ricinoleic acid, and lead salts of branched fatty acids such as oxo process carboxylic acids and neo acids, especially carboxylic acids represented by the following formula:

ALA

R2 R -0-COOH

R

3 wherein R 1 stands for a long-chain alkyl group, especially an alkyl group having 6 to 20 carbon atoms, R 2 stands for a lower alkyl group, especially an alkyl group having up to 6 carbon atoms, and R 3 stands for a hydrogen atom or a lower alkyl group, such as 2-ethylene-hexonic acid, isodecanoic acid, 9 isododecanoic acid, isotetradodecanoic acid, neodecanoic acid and neotetradodecanoic acid.

As the basic lead salt, there can be mentioned tribasic lead sulfate, tetrabasic lead sulfate, dibasic lead phosphite, basic lead carbonate, basic lead sulfite, basic lead silicate, basic lead phthalate and basic lead maleate.

The tin type stabilizer can be used in combination with the lead type stabilizer for improving the weatherability. A tin maleate type stabilizer or tin laurate type stabilizer having no risk of contamination So can be used as the tin type stabilizer.

The metal soap type stabilizer can be effectively used in combination with the lead type stabilizer for adjusting gelation and imparting a heat resistance.

0* It is preferred that the lead type Ptabilizer be used in an amount of 0.1 to 5 parts by weight, especially 0.3 to 2.5 parts by weight, per 100 parts by weight of the chlorine-containing polymer. It is amount o 20 of the lead type stabilizer is too small and below the Sabove-mentioned range, the heat stability of the pipe is ,.oo insufficient. If the amount of the lead type stabilizer a 0 is too large and exceeds the above-mentioned range, control of the elusion of lead becomes insufficient, and 25 use of such a large amount of the lead type stabilizer .o o is not preferred from the economical viewpoint.

In view of the moldability into a pipe, it is preferred that the weight ratio of the basic lead salt to the lead salt of the fatty acid be lower than 1, especially lower than In order to attain a bulking effect at the molding step, improve the pipe moldability, adjust the strength and hardness and attain an auxiliary heat stabilizing effect, calcium carbonate is incorporated into the chlorine-containing polymer. As the calcium carbonate, 10 there can be used light calcium carbonate, heavy calcium carbonate, gluey calcium carbonate and a mixture thereof. In view of the dispersibility, calcium carbonate having the surface coated with a metal soap or resin soap is advantageously used.

It is preferred that calcium carbonate be used in an amount of 0.01 to 15 parts by weight, especially to 10 parts by weight, per 100 parts by weight of the chlorine-containing polymer. If the amount of calcium carbonate is too small and below the above-mentioned range, the above-mentioned improvements by incorporation of the filler cannot be attained. If the amount of calcium carbonate exceeds the above-mentioned range, no Ssatisfactory results can be obtained with respect to 15 control of elusion of lead or increase of the pipe strength.

j In order to improve the pipe moldability, it is generally preferred that a lubricant be incorporated.

I ,fit. As the lubricant, there can be used paraffin, i 20 chlorinated paraffin, polyethylene wax, polypropylene i wax, oxidized polyethylene wax, microcrystalline wax, i montan wax, higher fatty acids, fatty acid amides, Shigher alcohols, higher fatty acid mono- and di-ester waxes, triglycerides, and metal soaps. It is preferred 1 25 that the lubricant be used in an amount of up to parts by weight, especially 0.01 to 2.0 parts by weight, per 100 parts by weight of the chlorine-containing polymer.

AL., The zeolite A to be used in the present invention, for example, the zeolite A of the Na type, has the following chemical composition.

1. I I 11 Chemical Composition Si0 2 AA203 Na20 ignition loss Fe 2 3 Fe203 CaO MgO General Range 35 to 45% 25 to 35% 13 to 20% 1 to 18% below 3% below 3% below 3% Preferred Range 36 to 27 to 33% 14 to 19% 15 to 17% below 1% below 0.1% below 0.1% 44 4) 4' O ut 04 4 4*41 4 C0 *it 4 I 4*

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44 4 4 *4tO SI I This alkali metal aluminosilicate has idea-ly a composition represented by the formula of Na 1 2(A2- 1 2 Si 1 2 04 8 )'1.5-30H 2 0, and the sodium component in the left portion of the formula is the portion capable of 15 catching hydrogen chloride.

This zeolite of the type A has, in general, an Xray diffraction pattern shown below.

X-Ray Diffraction Pattern Spacing d (KX) 12.440 8.750 7.132 5.5345 4.3708 4.1106 3.720 3.421 3.2995 2.9857 2.9098 2.7526 2.6270 2.5129 2.4661 Relative Intensity (I/In) 65.3 58.5 48.3 41.6 17.8 95.8 33 81.4 100 24.6 27.2 70.4 13.6 11.0 -12- It is preferred that the X-ray diffraction pattern of the alkali metal aluminosilicate be substantially the same as the X-ray diffraction pattern shown above, but according to the kind of the process for the synthesis of the alkali metal aluminosilicate, the relative intensity of each diffraction peak differs to some extent, namely within especially within Of course, an alkali metal aluminosilicate having such an X-ray diffraction pattern can also be advantageously used for attaining the objects of the present invention.

a o i, As pointed out hereinbefore, this zeolite A has a a hydrogen chloride capture quantity of at least 3 m 5 especially 5 to 10 mu/g.

15 The zeolite A used in the present invention has S0such a characteristic that the zeolite catches hydrogen 0 chloride preferentially to calcium carbonate. However, even if calcium carbonate reacts with hydrogen chloride oCO and calcium carbonate is formed, since the zeolite of o 20 the type A used in the present invention has a high ion exchange capacity to calcium chloride, the presence of residual calcium chloride is avoided. The ion exchange caoacity of the zeolite A to calcium chloride is at least 2.1 meq/g, especially at least 3.0 meq/g.

S: 25 A sodium type is most preferable for the zeolite A used in the present invention. However, up to 70 mole%, especially up to 60 mole%, of Na20 may be substituted by a polyvalent metal such as calcium, magnesium or zinc.

It is preferred that the zeolite of the type A used in the present invention should have a hydrochloric acid titration curve as shown in Fig. 2. In Fig. 2, the titration amount (milliequivalents) of HC2 per 100 g of the anhydrous zeolite is plotted on the abscissa, and the pH value of the system is plotted on the ordinate.

From Fig. 2, it is seen that the titration curve of the

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13 zeolite preferably used in the present invention has a large-inclination portion at the initial stage of the titration and a subsequent small-inclination portion, that is, a portion of a small reduction of the pH value.

More specifically, the zeolite of the type A preferably used in the present invention is characterized in that the maximum pH reduction gradient (Rmax) determined from the tangential line of the maximum gradient portion in the titration curve of Fig. 2 is generally -0.1 to -0.7 pH/meq HC) per 100 g of the zeolite especially -0.2 to 'I -0.5 pH/meq HC per 100 g of the zeolite, and the I ,it maintenance pH reduction gradient (Rmain) determined Ott from the tangential line of the subsequent smalli inclination portion of the titration curve is generally S 15 -0.001 to -0.07 pH/meq HCA per 100 g of the zeolite, especially -0.005 to -0.04 pH/meq HCA per 100 g of the iI zeolite.

In the zeolite of the type A used in the present 2 invention, it is construed that it is the alkali metal 20 or alkaline earth metal component corresponding to the .,,maximum pH reduction gradient (Rmax) portion that is effective for prevention of elusion of lead from the chlorine-containing polymer (prompt capture of hydrogen ji chloride). It also is construed that it is the alkali S 25 metal or alkaline earth metal component corresponding'to the maintenance pH reduction gradient (Rmain) that is effective for heat-stabilizing the pipe oc the chlorine- Scontaining polymer.

The zeolite of the type A having such titration characteristics can be obtained according to methods described in the examples given hereinafter.

In the zeolite of the type A, it is preferred that the primary particle size (particle size determined from an electron micrQscope photograph) be smaller than microns, especially smaller than 5 microns, and the 14 secondary particle size (determined by the sedimentation method) be smaller than 20 um, especially smaller than Jum.

It is preferred that the zeolite A be incorporated in an amount of 0.01 to 3.0 parts by weight, especially 0.2 to 1.5 parts by weight, per 100 parts by weight of the chlorine-containing polymer. If the amount of the zeolite is too small and below the above-mentioned range, the effect of controlling the elusion of lead in the presence of calcium carbonate is not sufficient, and if the amount of the zeolite A is too large and exceeds "I the above-mentioned range, initial coloration is often caused in the molded resin article.

SincorA pigment and other known additives can be i 15 incorporated in the chlorine-containing polymer 0 *,composition of the present invention in addition to the above-mentioned ingredients.

The resulting composition is supplied to a hopper I of a melt-kneading extruder and melt-kneaded, and if 20 necessary deaeration is effected, and the melt is Iextrusion-molded through an annular die or a sizer to obtain a pipe. The melt-kneading temperature is changed according to the kind of the resin, but it is *generally preferred that the melt-kneading temperature be 160 to 210"C.

The present invention will now be described in detail with reference to the following examples that by no means limit the scope of the invention.

J The methods adopted for determining various characteristics in the examples are described below.

Na20 and CaO Contents by weight) A sample dried at 110"C for 4 hours was subjected to the chemical analysis and an atomic absorption spectrometer was used for the determination.

Water Content by weight) 15 A sample was heat-treated at 850"C for 30 minutes and the decrease of the weight was measured as the ignition loss.

Average Particle Size (PU) The average particle size was measured by a Coulter Counter, Model TA-II, by using a aperture tube.

Hydrogen Chloride Capture Quantity (ml/g) A 0.4N aqueous solution of hydrochloric acid was added with stirring at a rate of 0.6 m2/min to an aqueous suspension of a zeolite of the type A having a concentration of 3 g/100 mj, and the quantity of ft hydrochloric acid consumed for reducing the pH value to 5 from 9 was measured as the hydrogen chloride capture quantity.

15 Smoothness of Inner Surface of Pipe lj The concavities and convexities of the inner surface of the pipe and the roughness of the inner surface of the pipe were observed with the naked eye, and 20 the smoothness was evaluated according to the following scale.

A: Small concavities and convexities, and reduced surface roughness B: small concavities and convexities, certain surface roughness C: prominent concavities and convexities Heat Stability (min) A pipe piece was placed in a gear oven maintained at 1900C, and the change of the degree of heat coloration was examined with the lapse of time (at intervals of 5 minutes). The time when the gray color was changed to the brown color was measured, and the heat stability was evaluated by this time (min).

Lead Elusion Quantity (ppb) According to. the method of JIS K-6724, a sample pipe was washed with city water (30 m/min) for I hour 16 and test water (calcium content 12 ppm, free residual chlorine content 1.0 to 1.2 ppm, pH 7.0 0.2) was sealed in the sample pipe and the pipe was allowed to stand still for 24 hours. Then, the amount of lead dissolved out into the test water was measured according to the dithizone method.

Example 1 This example illustrates the effect of controlling the elusion of lead by incorporating a zeolite of the type A in a water service pipe of a rigid polyvinyl ,chloride composition containing a lead type stabilizer and a calcium carbonate filler.

Preparation of Zeolite of Type A The zeolite of the type A used in this example was 15 prepared in the following manner.

As the starting SiO 2 material, a finely divided silicate having the particle size i.stribution and chemical composition shown in Table 1, which was obtained by acid-treating acid clay produced at Nakajo, S" 20 Niigata-ken, Japan, a clay mineral belonging to the smectite group, was used.

Table 1 Particle Size Distribution Particle Size Content by weight) 0 1 49.3 1 2 37.3 2 3 13.0 above 3 0.4 17 Chemical Composition Component Content by weight) ignition loss 3.93 SiO 2 94.10 A203 1.05 Fe 2 0 3 0.15 CaO 0.49 MgO 0.10 Commercially available sodium aluminate (Na 2 0 21.0%, A) 2 0 3 18.8%) and commercially available caustic soda were used as the starting Ai 2 0 3 and Na20 materials.

Is The respective starting materials were mixed and So .formed into a homogeneous aqueous slurry in which the SNa20/SiO 2 molar ratio was 1.2, the SiO2/AM20 molar C. 00 C i 2 2 2 6° o 15 ratio was 2.0 and the H 2 0/Na20 molar ratio was 35. The S slurry was heated at 95"C and reacted with stirring for 3 hours. By this reaction, crystal grains of an alkali metal aluminosilicate (zeolite of the 4A type) were 0. formed. Then, the slurry was aged at 95'C for 2 hours, and the slurry was filtered and deionized water was added to the obtained filter cake to form a homogeneous slurry. The slurry was filtered again and a cake of the zeolite 4A was recovered. The calcium exchange capacity of the obtained zeolite 4A as the product dried at 110'C was 6.2 meq/g as calculated as CaO.

The obtained zeolite 4A cake was dried at 110, 350 or 600C for 1 hour. Samples NA-11, NA-12, and NA-13 were tnus obtained. Separately, the obtained zeolite 4A All icake was thrown in a solution of calcium chloride to form a homogeneous slurry, and the slurry was stirred for 2 hours to effect ion exchange with the calcium ion.

Then, the slurry was filtered, washed and dried. Thus, ion-exchanged zeolite A samples CA-11, CA-12 and CA-13 were obtained. The properties of the obtained samples are shown in Table 2.

~--~CCUm Table 2 Sample N, contft(% by weight) CaO content by weight) Ignition loss by weight) 19.9 NA-11 NA-12 NA-13 CA-ji CA-12 CA-13 17.1 19.2 19.9 12.8 8.3 6.3 Heat treatment tef! erature, C) 1-10 350 600 Average particle size (jum).

2.15 2.15 2.18 5.8 2.3 20.3 20.8 20.4 Hydrogeai chloride capture quantity (ml/g) 9.72 6.82 6.03 4.11 3.74 2.17 2.17 3.53

A

b.- ~IILC~ II. i i 'r~ulCr~LI~ If ai~ 19 All

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Preparation of Polyvinyl Chloride Pipe A water service pipe of a rigid polyvinyl chloride resin was prepared by using the so-prepared zeolite A in the following manner.

To 100 parts by weight of a vinyl chloride resin having an average polymerization degree P of 1050 were added a lead type stabilizer comprising 0.2 part by weight of tribasic lead sulfate and 1.8 parts by weight of lead stearate, 3.0 parts by weight of heavy calcium carbonate, 0.2 part by weight of a polyethylene type 0 lubricant, 0.3 part by weight of a gray pigmen ,nd the .o above-mentioned zeolite A in an amount shown in Table 3, and the obtained polyvinyl chloride compound was O. extrusion-molded to obtain a service water rigid 15 polyvinyl chloride pipe (hereinafter referred to as "polyvinyl chloride pipe") having an inner diameter of 13 mm.

With respect to each of the so-obtained polyvinyl chloride pipes, the elusion quantity of lead, the inner surface smoothness, heat stability and other properties were determined according o the above-mentioned methods.

The obtained results are shown in Table 3.

4--4 r- OOS COO Table 3 Composition (parts by weight) Zeolite of type A NA-11 NA-12 NA-13 CA-11 CA-12 CA-13 tribasic lead sulfate lead stearate calcium carbonate polyethylene type lubricant gray pingment 1 0.3 2 0.5 0.2 1.8 3.0 0.2 0.3 Run No.

3 4 5 6 7 8 0.15 1.65 3.0 0.2 0.3 0.2 1.8 3.0 0.2 0.3 0.2 1.65 3.0 0.2 0.3 0.2 1.8 0.2 0.3 Characteristics of pipe inner surface smoothness B A A A B A A A heat stability (min) 65 70 75 70 65 70 65 lead elusiott quantity (ppbN 47 21 10 24 30 36 41 44 21 0 0 0 a0 0 0 00 0U 0 000 0 is 0 0 A0 0 4 4 t I From the foregoing results, it is seen that a zeolite of the type A having a hydrogen chloride capture quantity of at least 3 mi/g is added to a polyvinyl chloride pipe, thai elusion quantity or lead from the polyvinyl chlorIde is controlled.

Example 2 In this example, a synthetic zeolite of the type A was prepared by using sodium silicate as the starting silicate material in the following manner, and polyvinyl chloride pipes were prepared by using this zeolite A and lead type stabilizers, calcium carbonate and lubricants shown below. The properties o the obtained polyvinyl chloride pipes were determined.

Preparation of Zeolite of Type A Commercially available water glass (sodium silicate No. 3, Na 2 0 content 9.5% by weight, SiO 2 27.0% by weight) as the starting silicate material was mixed with commercially available sodium aluminate (Ai 2 0 3 22.5% by weight, Na20 5.5% by weight) and commercially available caustic soda (NaOH) so that the Na 2 O/SiO 2 molar ratio was 2, the SiO 2 /A2 2 0 3 molar ratio was 2 and the H 2 0/Na 2 0 molar ratio was 60. In a stainless steel vessel having a capacity o 5 water was added to the mixture and a starting dispersion having an entire quantity of about 1 kg was gradually prepared over a long time at room temperature (aboutt 25'C), whereby an entirely homogeneous alkali metal aluminosilicate gel was obtained. The formed gel dispersion was subjected to crystallization reaction at 94"C for 24 hours, and then, aging was conducted at 950C for 2 hours. The slurry was filtered, washed with water and washed with a O.IN aqueous solution o hydrochloric acid, and the obtained zeolite cake was dried at 110'C, 3504C or 600"C for 1 Iour. Zeolite 4N powder samples NA-21, NA-22 and NA-23 were thus obtained.

-22 Separ:atel~y. the obtained zeolite 4A cake wk, subjected to the ion exchange treatment, filtration and water washing in the same manner as described in Example 1. Then, the filter cake was dried at 1104*C. Ionexchanged zeolite A powder samples CA-21, CA-22 and CA- 23 were thus obtained.

The properties or the so-obtained zeolite A samples are shown in Table 4.~ ion 11 0 154J 4 c" 0 0 2 el 2 0 C~ 000 000 000 0 0 0 0 0 0 0 000 C t~0 0 0 f 0 C C 00 Or 0 0 0 0 000 00 0 0 0 000 ~s 0 0 0 0 0 0 0 0 00 0 Samrle "Gcontt(7 by weight) NA-21 1.

NA-22 18.2 NA-23 16.9 CA'-21 6.7 CA-22 5.4 CAi-23 2.1 Table 41 CaO con- Ignition tent by loss weight) by weight) 19.9 6.2 Heat treat- Average Hydrogen chloment tenij e- particle ride capture rature size q cuantity (ml/g) 110 2.15 9.72 350 2-.16 13.33 600 7.57 3.16 '110 2.17 3.53 1-10 7.38 2.28 110 2.23 1.21 9.5 11.8 141.4 2 .7 20.4 19.2 20-8 24 Preparation of Polyvinyl Chloride Pipe In the same manner as described in Example 1, 100 parts by weight of a vinyl chloride resin having an average polymerization degree P of 1050 were mixed with amounts, shown in Table 5, of the so-prepared zeolite A, a stabilizer,, calcium carbonate, a lubricant and a gray pigment, and the resulting compound was extrusion-molded to obtain a water service rigid polyvinyl chloride pipe having an inner diameter of 13 mm.

10 With respect to each of the so-obtained polyvinyl S<o chloride pipes, he properties were determined according 0 to the above-mentioned methods. The obtained results EO are shown in Table In order to clearly demonstrate the effects of the ou 15 present invention, comparative samples (Runs 22 through 33 shown in Table 5) were similarly tested. The obtained results are shown in Table 0 l o 0 0 O

I

OOD #00 ~00 #00 00 0 0 00 0 00 0 04 000 0 0 Composition (parts by weight) Zeolite of' type A NA-21 NAi-22 NA-23 CA-21 CA-22 CA-23 tribasic lead sulfate dibasic lead stearate lead stearate calcium carbonate polyethylene type lubricant fatty acid ester type lubricant gray pigment Characteristics of Pipe inner surface smo~othness heat stability (min) lead elusion quantity (ppb) Table Run No. (present invention) 9 10 11 12 13 14{ 15 16 17 18 19 20 21 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.2 0.2 0.2 0.2 0.5 0.2 0.2 0.2 1.8 3.0 0.2 o.4I 1.8 1.8 1.2 3.0 3.0 3.0 0.2 1.8 1.8 1.0 0.2 0.2 1.8 1.8 0.2 0.2 0.3 0.6 0.3 0.3 0 .3 0.3 0.3 0 0.3 0.3 0.3 0.3 0.3 0.3 0.3

A

60 20

B

K

Table 5 (continued) Composition (part& by weight) Zeolite of type A NA-21 NA-22 NA-23 Cej-21 CA-22 CA-23 tribasic lead sulfate dibasic lead stearate, lead stearate calcium carbonate polyethylene type lubricant fatty acid ester type lubricant gray Pigmnt Characteristics of* Pipe inner surface smoothness heat stability (run) lead elusion quantity (ppb) Run No. (comparison) 22 23 241 25 2 6_ 27 28 29 30 31i .32 33 0.5 0.2 0.2 0.8 1.0 0.2 0.2 0.2 0.2 1L8 3.0 0.2 1.8 3.0 0.2 0. 0.5 1.8 1.8 3.0 3.0 1.0 0.2 0.2 1.0 1.8 3.0 0.2 1.8 1.8 1.0 0.2 0.2 1.8 0.2 0.3 0.3 0.3 0.3 0.3 G-3 0.3 0.3 0.3 0.3 0.3 0.3 B B B 60 60 85 96 64i 108 110 122 128 156 6o 641 78 27 From the foregoing results, it is seen that if the composition specified in the present invention is given to a vinyl chloride resin for a water service pipe and the specific zeolite is incorporated according to the present invention, elusion of lead from a water service rigid polyvinyl chloride pipe can be prominently controlled.

Example 3 A water service polyvinyl chloride pipe was prepared in the same manner as described in Example 1 |j except that a lead stabilizer comprising a combination S of a lead salt of a fatty acid and a tin type stabilizer S\ or metal soap type stabilizer, shown in Table 6, was used as the stabilizer. The effect of controlling the ii 15 elusion of lead was examined in the same manner as described in Example 1. The obtained results are shown in Table 6.

4 0

-I

4, 04 00 4 4 400 0040 4 4 4 494 0 4*9 4 *00 994 99., Composition (parts by weighit) Zeolite butyl tin maleate polymer lead stearate calcium carbonate polyethylene type lubricant gray pigment Characteristics of* Pipe inner surface smoothness heat stability (min) lead elusion quantity (ppb) Table 6 (present invention) 0.5 0.5 0.25 0.2 0.3 0.2 1.8 1.8 1.8 3.0 3.0 3.0 0.2 0.2 0.2 0.3 0.3 0.3 (comparison) ~37 38- 0.2 1.8 3.0 0.2 0.3

B

60 77i 0.2 1.8 0.2 0.3

B

78

I

II

Claims (9)

1. A water service pipe which is composed of a resin composition comprising 100 parts by weight of a chlorine-containing polymer, 0.1 to 5.0 parts by weight of a lead type stabilizer comprising a lead salt of a fatty acid, a combination of a lead salt of a fatty acid and a basic lead salt, a combination of a lead salt of a fatty acid and a tin type stabilizer or a combination of a lead salt of a fatty acid and a metal soap type stabilizer, 0.01 to 15 parts by weight of a calcium carbonate filler, up to 5.0 parts by weight of a lubricant and 0.01 to 3.0 parts by weight of a zeolite of the type A. 15 2. A water service pipe as set forth in claim 1, S" wherein the zeolite of the type A is a zeolite of the sodium type and/or calcium type and the hydrogen chloride capture quantity of the zeolite, defined as 1, o the quantity of hydrochloric acid necessary for reducing the pH value of the zeolite to 5 from 9 by using a 0.4N aqueous solution of hydrochloric acid, is at least 3 m /g.

3. A water service pipe as set forth in claim 1, wherein the zeolite of the type A is a zeolite having such characteristics that the maximum reduction gradient (Rmax) determined from the tangential line of the maximum gradient portion of the hydrochloric acid titration curve is -0.1 to -0.7 pH/meq HC per 100 g of the zeolite, and the maintenance pH reduction gradient (Rmain) determined from the tangential line of the subsequent small-inclination portion of the hydrochloric acid titration curve Ls -0.001 to -0.07 pH/meq HCI per 100 g of the zeolite.

4. A water service pipe as set forth in claim 1, wherein the chlorine-containing polymer is a vinyl chloride resin. i A water service pipe as set forth in claim 1, wherein the lead salt of the fatty acid is lead stearate.

6. A water service pipe as set forth in claim 1, wherein the basic lead salt is tribasic lead sulfate.

7. A water service pipe as set forth in claim 1, wherein the tin type stabilizer is a butyl-tin maleate polymer.

8. A water service pipe as set forth in claim 1, wherein the metal soap stabilizer is a calcium stearate.

9. A water service pipe as set forth in claim i, wherein the lubricant is at least one member selected from the group consisting of paraffin, chlorinated paraffin, polyethylene I wax, polypropylene wax, oxidized polyethylene wax, microcrystalline wax, montan wax, higher fatty acids, fatty acid amines, higher alcohols, higher fatty acid mono- and j l di-ester waxes, triglycerides, and metal soaps. A one-package additive for a chlorine-containing polymer, which comprises a lead type stabilizer comprising a lead salt of a fatty acid, a combination of a lead salt of a fatty acid and a basic lead salt, a combination of a lead salt of a fatty acid and a tin type stabilizer or a combination of a lead salt of a fatty acid and a metal soap type stabilizer, (ii) a calcium carbonate filler, (iii) a lubricant and (iv) a zeolite of the type A, said components through (iv) being !i mixed so that the amounts of the components through (iv) it 25 are 0.1 to 5 parts by weight, 0.01 to 15 parts by weight, up Sto 5 parts by weight and 0.01 to 3 parts by weight, respectively, per 100 parts by weight of the chlorine- containing polymer.

11. A one-package additive as set forth in claim I 30 wherein the zeolite of the type A is a zeolite having such ij characteristics that the maximum reduction gradient (Rmax) j determined from the tangential line of the maximum gradient portion of the hydrochloric acid titration curve is -0.1 to -0.7 pH/meq HC% per 100 g of the zeolite, and the maintenance pH reduction gradient 39 Ss) -0 cI s r l l 'l 31 (Rmain) determined from the tangential line of the subsequent small-inclination portion of the hydrochloric acid titration curve is -0.001 to -0.07 pH/meq HC2 per 100 g of the zeolite.

12. A stabilizer for a chlorine-containing polymer, which comprises sodium aluminosilicate or calcium aluminosilicate having an X-ray diffraction pattern inherent to a zeolite of the type A or a mixture thereof, wherein the hydrogen chloride capture quantity defined as the quantity of hydrochloric acid necessary for reducing the pH value of the zeolite to from 9 by using a 0.4N aqueous solution of hydrochloric ,t acid is at least 3 the maximum reduction gradient (Rmax) determined from the tangential line of the 15 maximum gradient portion of the hydrochloric acid Stitration curve is -0.1 to -0.7 pH/meq HC per 100 g of the zeolite, and the maintenance pH reduction gradient SIt',l (Rmain) determined from the tangential line of the subsequent small-inclination portion of the hydrochloric acid titration curve is -0.001 to -0.07 pH/meq HC. per 100 g of the zeolite. DATED: 24 January, 1989 I PHILLIP ORMONDE FITZPATRICK Attorneys for: *W MIZUSAWA INDUSTRIAL CHEMICALS, LTD 9 a/ A nh I