JP2002295741A - Pipe material of polypropylene-based resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe material of thermo plasticity having heat resistance and flexibility, suited for use in even a cold district. SOLUTION: A rubber-state polymer of olefinic elastomer or styrene-based elastomer and a polypropylene-based resin are mixed at a ratio of 40/60 to 90/10 by weight, the rubber-state polymer is dynamically cross-linked under coexistence of a cross linking agent, the polypropylene-based resin is newly mixed as necessary in an obtained resin composition, the cross-linked rubber- state polymer and the polypropylene-based resin are included at a ratio of 5/95 to 70/30 by weight, a polypropylene-based resin composition having finely scattering rubber-state polymer grains in a polypropylene-based resin phase is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hot water supply and pipe materials for water supply, and more particularly to a pipe material used for hot water supply.

[0002]

2. Description of the Related Art At present, there is a demand for plastic pipes made of polyolefin resin such as flexible cross-linked polyethylene pipes and polybutene pipes in place of conventional metal pipes for hot water supply and water supply pipes in buildings such as houses. Is expanding.

[0003] Compared with conventional metal pipes, plastic pipes made of polyolefin resin, especially high-density polyethylene (HDPE) pipes, are not only lightweight, earthquake-resistant and rust-proof, but also require new construction methods. Excellent in performance such as easiness (plumbing method such as sheath pipe header method and new pipe joining method such as electrofusion). However,
HDPE pipes have insufficient heat resistance, and particularly have poor rigidity at high temperatures, resulting in poor heat creep resistance and are not suitable for hot water supply applications. A flexible pipe is preferred for hot water supply because it is easy to construct, but the HDPE pipe lacks this flexibility.

[0004] In Japan and Europe, polypropylene (PP) pipes have begun to be used as pipes having higher heat resistance, although they have hardly been used in Japan. However,
PP tubes have poor low-temperature properties, especially low-temperature impact resistance, and
It lacks flexibility and is not suitable for hot water supply applications.

[0005] Therefore, as hot water supply pipes, crosslinked polyethylene pipes and polybutene pipes having excellent heat resistance and flexibility are common in the market.

[0006]

However, the above-mentioned crosslinked polyethylene pipe and polybutene pipe have the following problems. (1) Cross-linked polyethylene pipes are cross-linked to improve the heat resistance of HDPE pipes. However, they are not recyclable, and a large amount of waste pipes generated when rebuilding houses is buried or destroyed. There is no other disposal method, which is a major problem. (2) The flexibility of the polybutene tube is slightly inferior. Also, the low-temperature impact resistance is poor. Therefore, it is not suitable for use in cold regions.

[0007] As described above, at present, there is no pipe material that sufficiently satisfies the performance required for hot water supply, water supply use, especially hot water supply use.

An object of the present invention is to provide hot water supply and water supply applications,
The purpose of the present invention is to provide an easy-to-install pipe material, specifically, having heat resistance and sufficient flexibility suitable for the above-mentioned applications,
An object of the present invention is to provide a pipe material which is excellent in thermal properties (high-temperature properties and low-temperature properties) which are thermoplastic and recyclable.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above problems, and as a result, a partially or completely crosslinked rubbery polymer and polypropylene (PP)
The composition composed of a base resin is thermoplastic and has recyclability, is excellent in thermal properties, is also excellent in low-temperature impact resistance, and can arbitrarily design pipes having various flexibility. This led to the completion of the present invention.

That is, the present invention provides at least (A) a partially or completely crosslinked rubbery polymer and (B) a polypropylene resin in a weight ratio of (A) / (B) = 5/95.
A polypropylene-based resin pipe material containing the rubber-like polymer and the polypropylene-based resin in a ratio of about 70/30 and having a phase-separated structure.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

First, each component of the present invention will be described.

The rubbery polymer as the component (A) of the PP resin pipe material of the present invention includes, for example, polybutadiene, aromatic vinyl / conjugated diene copolymer or hydrogenated aromatic vinyl / conjugated diene copolymer Rubber such as styrene, acrylonitrile / conjugated diene copolymer, acrylic rubber such as isoprene rubber, chloroprene rubber and polybutyl acrylate; and copolymer rubber of ethylene and α-olefin, vinyl acetate, acrylate or methacrylate. And the like.

Of these, olefin-based elastomers and styrene-based elastomers are particularly preferred because of their excellent mechanical strength and the like. As the olefin elastomer, ethylene / α-olefin copolymer rubber containing ethylene and α-olefin as main components as monomer components,
Alternatively, a polymer having a similar structure can be used. Examples of the styrene-based elastomer include an aromatic vinyl / conjugated diene copolymer and a hydrogenated conjugated diene copolymer.

The ethylene / α-olefin copolymer rubber contains at least ethylene and α-olefin as monomer components.
An olefin is contained as a main component, and the α-olefin is preferably contained in the main component in an amount of 1 to 60% by weight, more preferably 10 to 50% by weight, and more preferably 20 to 45% by weight. When the content of α-olefin in the main component is less than 1% by weight, rubber elasticity is inferior,
If it exceeds 50% by weight, the strength tends to decrease. As the α-olefin, it is preferable to use an α-olefin having 3 to 20 carbon atoms. Α having 3 to 20 carbon atoms
-As the olefin, for example, propylene, butene-
1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, and the like. These α-olefins may be used alone or in combination of two or more.

Further, the ethylene / α-olefin copolymer rubber can contain a third copolymer component. As the third copolymer component, 1,3-butadiene,
Conjugated dienes such as isoprene, dicyclopentadiene,
Non-conjugated dienes such as 1,4-hexadiene, cyclooctadiene, methylenenorbornene, and ethylidene norbornene are exemplified. Ethylene containing a third copolymer component /
Examples of the α-olefin-based copolymer rubber include ethylene / propylene / conjugated or non-conjugated diene terpolymer rubber (EPDM). Among these, copolymer rubbers of ethylene and hexene-1, 4-methylpentene-1 or octene-1 and EPD
M can be mentioned as a preferred example. Further, among these, copolymer rubbers of ethylene and octene-1 and EPDM, particularly those produced with a metallocene catalyst, are preferred. Furthermore, among these, a copolymer rubber of ethylene and octene-1 produced with a metallocene catalyst does not contain a double bond in the molecule, and thus a pipe made of a resin composition containing the copolymer rubber is Excellent weather resistance,
Most preferred. The content of the third copolymer component is preferably 50% by weight or less in the copolymer rubber.
More preferably 40% by weight or less, desirably 30% by weight
It is as follows.

Further, as a polymer having a structure similar to the above-mentioned ethylene / α-olefin copolymer rubber,
For example, a rubber obtained by hydrogenating polybutadiene, which is structurally similar to an ethylene / butene-1 copolymer, may be used.

The above ethylene / α-olefin copolymer rubber has a melt index (MFR, measurement condition: 190
(C, 2.16 kg load) in the range of 0.01 to 50 g / 10 min is preferably used, and more preferably 0.05 to 20 g / 10 min. MFR 50g /
If the time exceeds 10 minutes, the rubber elasticity of the rubbery polymer is insufficient. Undesired.

The above-mentioned aromatic vinyl / conjugated diene copolymer and hydrogenated aromatic vinyl / conjugated diene copolymer, which are preferable as the styrene elastomer, may be random copolymers or block copolymers. And a block copolymer may be included in the random copolymer.

The hydrogenated block copolymer will be described in detail. The block copolymer comprises a polymer block (S) mainly comprising at least one aromatic vinyl compound.
And a block copolymer consisting of at least one hydrogenated conjugated diene-based polymer block (B). Its structure is, for example, SB, SBS, BS
-B-S, and the like (S-B) _n Si. Examples of the conjugated diene include butadiene and isoprene.

Specific examples of the aromatic vinyl / conjugated diene copolymer include styrene / butadiene random or block copolymers, styrene / isoprene random or block copolymers, and hydrogenated products thereof.

The amount of aromatic vinyl in the aromatic vinyl / conjugated diene copolymer is preferably 70% by weight or less, more preferably 60% by weight or less, and further preferably 50% by weight or less. When the amount of aromatic vinyl exceeds 70% by weight, rubber elasticity is lacking, and the effect of imparting flexibility to the pipe material of the present invention is low.

Further, the conjugated diene in the aromatic vinyl / conjugated diene copolymer preferably has a 1,2-vinyl bond and a 1,4-vinyl bond. By having both 1,2 vinyl bond and 1,4 vinyl bond in the molecule, rubber elasticity is increased, impact resistance of the pipe material of the present invention is improved, and glass transition temperature (Tg) is lowered, Low temperature characteristics also increase. The 1,2-vinyl bond content of the conjugated diene is preferably from 5 to 95%, more preferably from 10 to 90%.
When the 1,2-vinyl bond content is less than 5% or more than 95%, the performance as an elastomer is low, and the effect of imparting flexibility to the obtained pipe material of the present invention is low. Furthermore, low-temperature characteristics are not preferable.

The above aromatic vinyl / conjugated diene copolymer has a melt index (MFR, measurement conditions: 190 ° C.,
2.16 kg load) is preferably used in the range of 0.01 to 20 g / 10 min, more preferably 0.1 to 10 g / 10 min. When it exceeds 20 g / 10 min, the rubber elasticity of the rubbery polymer is insufficient, and when it is less than 0.01 / 10 min, the fluidity when forming a pipe using the pipe material of the present invention is poor, Undesirably, the workability is reduced.

Further, the crosslinking of the rubbery polymer as the component (A) according to the present invention will be described.

The rubbery polymer used in the present invention needs to be partially or completely crosslinked. The reason is that when not cross-linked, when forming a pipe using the pipe material of the present invention, the resin is stretched in the flow direction to perform orientation treatment, but when the rubber-like polymer is cross-linked, The shape of the raw rubber-like polymer is maintained in the molded article without being stretched in the flow direction, thereby,
This is because the impact resistance is improved. When an uncrosslinked rubbery polymer is used, the rubbery polymer is stretched and oriented in the flow direction by the above-mentioned orientation treatment, and a sufficient effect of improving impact resistance cannot be obtained. Furthermore, even if the non-crosslinked rubber-like polymer is finely dispersed in the composition, the rubber-like polymer of the rubber-like polymer in the molded article tends to become extremely large during the cooling process of the pipe molding process ( In the industry, it is generally called spinodal decomposition), the rubber reinforcing effect is reduced, and the impact resistance improving effect is small. The degree of crosslinking of the rubbery polymer used for the pipe material of the present invention is preferably 10% or more, more preferably 30% or more, more preferably 70% or more, and desirably 80% or more. When the degree of crosslinking is less than 30%, the pipe material of the present invention has low mechanical strength such as impact resistance.

The rubbery polymer of the component (A) used in the present invention preferably has a glass transition temperature (Tg) of -30 ° C. or lower. When the Tg of the rubbery polymer is −30 ° C. or less, the low-temperature impact resistance of the pipe material of the present invention (particularly, −
(Drop impact strength at 30 ° C.) is high, and is suitable as a pipe material for cold regions.

Next, the P of component (B) used in the present invention
The P-based resin will be described.

The PP resin used in the present invention includes:
Examples thereof include a polypropylene homopolymer or a copolymer resin (including block and random) of propylene with another α-olefin such as ethylene, butene-1, pentene-1, and hexene-1.

The component (B) used in the present invention is a component constituting a matrix of the pipe material of the present invention. In order to enhance the heat resistance of the pipe material, a polypropylene homopolymer or ethylene copolymerized with propylene is used. Alternatively, a copolymer containing 10% by weight or less of an α-olefin copolymer component is preferable.

The melt index (M
FR, measurement conditions: 230 ° C, 2.16 kg load)
The range is preferably 0.01 to 50 g / 10 minutes, and more preferably 0.05 to 50 g / 10 minutes. When it exceeds 50 g / 10 minutes, the mechanical strength and heat resistance of the pipe material of the present invention are insufficient, and 0.01 g / min.
If the time is less than 10 minutes, the flowability is poor when forming a pipe using the pipe material of the present invention, and the molding processability is undesirably reduced.

The above PP resin may be used alone.
Two or more kinds may be used in combination.

The pipe material of the present invention is, as described above,
(A) It contains at least a partially or completely crosslinked rubbery polymer and (B) a PP resin, and the compounding ratio thereof is (A) / (B) = 5/95 to 70 / by weight ratio. 95
It is. That is, in the mixture of the component (A) and the component (B), the component (A) is 5 to 70% by weight, preferably 5 to 4% by weight.
0% by weight, more preferably 10 to 30% by weight, and desirably 15 to 25% by weight. When the amount of the component (A) is less than 5% by weight, the effect of improving impact resistance, particularly low-temperature impact resistance, is not sufficient. If it exceeds 40% by weight, the rigidity tends to decrease, which is not preferable.

Next, features of the pipe material of the present invention will be described.

(1) The pipe material of the present invention comprises a partially or completely crosslinked rubbery polymer (soft component) as component (A) and a PP resin (hard component) as component (B). It has a morphology with a phase separation structure. FIG. 1 shows a micrograph of the pipe material of the present invention (TPV-1 of Example 1 described later). The white part of the photograph is the PP light resin phase of the continuous phase, and the black part is the rubbery polymer phase of the dispersed phase.

In general, this phase separation structure has a so-called sea-island structure in which a PP resin is a matrix (continuous phase) and a crosslinked rubber-like polymer forms a small-particle dispersed phase. The particle diameter of the constituent crosslinked rubber-like polymer particles is in the range of 0.01 to 10 μm. Accordingly, the pipe material of the present invention is thermoplastic, has excellent extrusion moldability, and can be recycled because the PP-based resin (B) serves as a fluid phase.

(2) Since the rubbery polymer of the component (A) used in the present invention is partially or completely crosslinked,
Low deformation at high temperature and excellent high temperature characteristics.

(3) Further, by using a rubbery polymer having a glass transition temperature (Tg) of -30 ° C. or lower as the component (A), a resin composition having more excellent low-temperature properties can be obtained. Can be.

(4) In the present invention, the ratio of the rubber-like polymer (soft component) to the PP resin (hard component) is arbitrarily changed to freely design pipes having flexibility, that is, different hardness. Can be. At this time, the hardness of the pipe material of the present invention is 50 to 7 in JIS D hardness (Shore D hardness).
It is preferably in the range of 5.

Next, a method for producing a pipe material according to the present invention will be described.

The pipe material of the present invention is preferably obtained by dynamically crosslinking an uncrosslinked rubbery polymer and a PP resin as the component (B) in the presence of a crosslinking agent. Here, the term “dynamic crosslinking” means that at least one of the resins is cross-linked at the time of mixing and melting two or more resins, so that the cross-linking reaction is performed while giving a shearing reaction. In the above, the reactant is reacted with a crosslinking agent while melt-kneading or stirring using a Brabender, Banbury mixer, kneader, extruder or reactor.

The ratio between the rubbery polymer and the PP resin at the time of the dynamic crosslinking is preferably 40/60 to 90/10 (weight ratio). Generally, when the PP-based resin is more than the rubber-like polymer, the crosslinking of the rubber-like polymer becomes insufficient, and the radical initiator used as the crosslinking agent is
It is presumed that the rubbery polymer is used for molecular cutting of the polypropylene resin without being used for crosslinking. On the other hand, in the pipe material of the present invention, the resin composition having a rubber-like polymer and a PP-based resin in a weight ratio of 5/95 to 70/30 and a rubber-like polymer content of less than 40% by weight is used. Cannot be produced in a single step of the dynamic crosslinking step at a preferred composition ratio of In such a case, once a new PP resin is mixed with the resin composition obtained by the dynamic crosslinking in the preferable range,
It is also possible to have a desired composition. For example, it is possible to use a twin-screw extruder, perform dynamic crosslinking in the first half of the twin-screw extruder, and add a PP resin near the middle.

When a new PP resin is mixed after dynamic crosslinking, the PP resin used for dynamic crosslinking and the PP resin added after dynamic crosslinking may be the same or different. . In the pipe material of the present invention, the pipe hardness can be freely designed by selecting the orientation ratio at the time of the above-mentioned dynamic crosslinking or after the dynamic crosslinking, and the flexibility can be controlled.

In the production of the pipe material of the present invention, examples of the crosslinking agent preferably used include radical initiators such as organic peroxides and organic azo compounds. Specific examples of the radical initiator preferably used as the crosslinking agent include 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1
-Bis (tert-hexylperoxy) -3,3,5
-Trimethylcyclohexane, 1,1-bis (tert
-Hexylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy) cyclododecane, 1,
1-bis (tert-butylperoxy) cyclohexane, 2,2-bis (tert-butylperoxy) octane, n-butyl-4,4-bis (tert-butylperoxy) butane, n-butyl-4, 4-bis (ter
peroxy ketals such as t-butylperoxy) valerate; di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, α, α'-bis (tert-butylperoxy-
m-isopropyl) benzene, α, α′-bis (ter
t-butylperoxy) diisopropylbenzene, 2,
Dialkyl peroxides such as 5-dimethyl-2,5-bis (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexyne-3; acetyl peroxide; Isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioil peroxide Diacyl peroxides such as tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy laurylate, tert- Chill peroxybenzoate, di -tert- butyl peroxy isophthalate, 2,5
-Dimethyl-2,5-di (benzoylperoxy) hexane, tert-butylperoxymaleic acid, ter
Peroxyesters such as t-butylperoxyisopropyl carbonate and cumylperoxyoctate; and tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2, 5-dihydroperoxide and 1,1,
Hydroperoxides such as 3,3-tetramethylbutyl peroxide can be exemplified.

Among the above compounds, 1,1-bis (te
rt-butylperoxy) -3,3,5-trimethylcyclohexane, di-tert-butyl peroxide,
Dicumyl peroxide, 2,5-dimethyl-2,5-
Bis (tert-butylperoxy) hexane and 2,
5-Dimethyl-2,5-bis (tert-butylperoxy) hexyne-3 is preferred.

These radical initiators are used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight of the rubbery polymer. The level of crosslinking is mainly determined by this amount. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if the amount exceeds 3 parts by weight, the crosslinking ratio is not greatly improved, so that it is not a preferable direction.

Examples of the crosslinking aid include divinylbenzene, triallyl isocyanurate, triallyl cyanurate,
Diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate,
Trimethylolpropane triacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, p-quinone dioxime, p, p'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N , N'-m-
Phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, butadiene and the like are preferably used. These crosslinking aids may be used in combination of two or more.

The crosslinking aid is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the rubbery polymer. If less than 0.1 part by weight, the degree of crosslinking is low,
Not preferred. If the amount exceeds 5 parts by weight, the degree of crosslinking is not significantly improved, which is not a preferable direction.

In the production of the pipe material of the present invention, it is preferable to use a cross-linking agent and a cross-linking assistant in combination as described above. In addition, a phenol resin or bismaleimide may be used as the cross-linking agent.

The pipe material of the present invention comprises at least (A)
It comprises a partially or completely crosslinked rubbery polymer as a component and an olefin resin as a component (B), and if necessary, other components such as a resin other than the olefin resin and a matrix PP. A nucleating material that promotes crystallization, a softener, an inorganic filler, a plasticizer, and the like can be used. Among them, the addition of nucleating material is PP
This is effective for improving the rigidity and heat resistance of the steel. Examples of the nucleating material include talc. The softener is effective for further improving the impact resistance of the pipe material of the present invention. As the softener, process oils such as paraffinic and naphthenic can be used. When a softener is added, it is used in an amount of 5 to 100 parts by weight based on 100 parts by weight of the rubbery polymer. If the amount is less than 5 parts by weight, the improvement effect is small and 10
If it exceeds 0 parts by weight, oil bleeding of the molded product becomes remarkable, which is not desirable. Examples of the inorganic filler include talc, calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, carbon fiber, whisker, titanium oxide, clay, mica, magnesium hydroxide, and aluminum hydroxide. Among them, talc is particularly effective in improving the rigidity or heat resistance of a molded article obtained by using the pipe material of the present invention. When talc is added, the amount is 5 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the PP resin composition as the pipe material of the present invention. Examples of the plasticizer include phthalic acid esters such as polyethylene glycol and dioctyl phthalate (DOP). Also, other additives, for example, organic and inorganic pigments,
Heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents and the like are also suitably used.

[0051]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows.

[Test Method] (1) Shore D hardness Measured with a JIS D hardness meter.

(2) Tensile strength: 23 ° C., 50 ° C., in accordance with JIS K6251
It was measured at 80 ° C.

(3) Elongation In the measurement of tensile strength, elongation was measured at 23 ° C. using a measuring instrument equipped with an extensometer.

(4) Flexural strength Measured at 23 ° C. by a method according to JIS K6758.

(5) Flexural modulus Measured at 23 ° C. by a method according to JIS K6758.

(6) Izod impact strength 23 ° C., -30 ° C. according to JIS K6758
(V notch, 1/4 inch test piece).

(7) Drop Weight Impact Test The ductile and brittle fractures were judged from the state of destruction of the plastic material due to the drop of the missile, and the practical impact resistance of the material was evaluated from the absorbed energy due to the fracture. Testing machine: Drop weight graphic impact tester type A (Toyo Seiki) Measurement conditions: Specimen: 3 mm thick Flat plate 10 × 10 cm Missile diameter: 12.7 mm Sample holder diameter: 50 mm Drop height: 100 cm Weight: 6.5 kg Measurement temperature : 23 ° C and -30 ° C

(8) Pipe Pressure Test A 35 cm long pipe was threaded at both ends, a metal plug was attached to one end, and a metal plug with two male screws was attached to the other end. Bonding was applied to the attachment part to give sufficient strength. This was gradually pressurized to a pressure of 1 to 10 MPa with a water pressure to obtain a breaking pressure of the pipe.

(9) Evaluation of Pipe Flexibility A crosslinked HDPE pipe, which is said to have a slight lack of flexibility in the market, was designated as Δ, and was evaluated relative to this. ×: insufficient flexibility △: slightly insufficient 〇: flexible ◎: sufficient flexibility

(10) Evaluation of Pipe Appearance The gloss, roundness, thickness unevenness, etc. of the pipe surface were comprehensively evaluated in four steps. ×: poor appearance △: slightly poor △: good appearance ◎: excellent appearance

(11) Smoothness of Pipe Surface Irregularities and roughness of the pipe surface were evaluated in four stages. ×: insufficient smoothness △: slightly insufficient smoothness 〇: good smoothness ◎: excellent smoothness

(12) Degree of Crosslinking 0.5 g of the sample was mixed with a solvent capable of dissolving both the non-crosslinked rubbery polymer and the polystyrene resin, for example, 200 ml of xylene.
Reflux for 4 hours in l. The solution was filtered through a filter paper for quantitative determination, the residue on the filter paper was vacuum-dried and quantified, and the ratio of the weight of the residue to the weight of the rubbery polymer in the sample (%)
It was calculated as

[Raw Materials] (1) Uncrosslinked rubbery polymer: TPE-1 (ethylene / octene-1 copolymer) It was produced by a method using a metallocene catalyst described in JP-A-3-16388. The ethylene / octene-1 composition ratio of the copolymer was 72/28 (weight ratio).

(2) PP resin: PP (polypropylene homopolymer) Isotactic homopolypropylene “MA03” manufactured by Nippon Polychem Co., Ltd. was used.

(3) Radical initiator: POX 2,5-dimethyl-2,5-bis (te) manufactured by NOF Corporation
rt-butylperoxy) hexane “Perhexa 25
B "was used.

(4) Crosslinking aid: DVB Divinylbenzene manufactured by Wako Pure Chemical Industries was used.

(Examples 1 to 3) As an extruder, a twin-screw extruder (40 mmφ, L / D
= 47, rotation in the same direction). As the screw, a double-threaded screw having a kneading portion before and after the injection port, a toughening type was used. TPE-1 / PP / POX / DVB = 5
5.0 / 44.0 / 0.38 / 0.74 (weight ratio) was mixed using a blender for 20 minutes to prepare a feed material. This feed material is melt-extruded at a cylinder temperature of 220 ° C., a rotation speed of 300 rpm, and a discharge rate of 75 kg / hr, pelletized, and subjected to a dynamically crosslinked PP resin composition (TPV-
1) was manufactured.

The thus obtained TPV-1 pellets and PP pellets were mixed in a weight ratio of 100/0, 50/5.
Each was blended at 0, 25/75 to obtain three types of pipe materials having different hardnesses. Using a single-screw extruder 50mm (with sizing device with ejector and water tank for water cooling),
A resin having a resin temperature of 200 ° C., a degree of vacuum of 25 mmHg, and a pipe take-up speed of 60 cm / min was extruded to produce a pipe having a diameter of 32 mm and a wall thickness of 3.0 mm.

(Comparative Examples 1 and 2) The following pipes were manufactured in order to evaluate the performance of flexible cross-linked HDPE pipes and polybutene pipes which were ahead of the market. For the crosslinked HDPE tube, reference was made to JP-A-9-208637.

MFR 2.1 polymerized with Ziegler catalyst
g / 10 min, density 0.938 g / cm ³ , Mw / Mn
2.7, 100 parts by weight of linear polyethylene containing 1.2 mol% of butene-1, 2.0 parts by weight of vinyltrimethoxysilane, 2,5-dimethyl-2,5-bis (te
rt-butylperoxy) hexane (0.03 parts by weight) was extruded using the 40 mmφ twin-screw extruder used in Example 1 at a set temperature of 230 ° C. and a screw rotation speed of 150 rpm, followed by heat grafting to obtain a silane-modified linear chain. A polyethylene was obtained. The obtained silane-modified linear polyethylene and a masterbatch containing 1.5 parts by weight of dioctyltin dilaurate in 100 parts by weight of the linear polyethylene before silane modification were blended at a weight ratio of 25: 1. The extruder used in Example 1 produced a pipe having a diameter of 32 mm and a wall thickness of 3.0 mm. The manufactured pipe was immersed in warm water at 80 ° C. for 24 hours to manufacture a crosslinked HDPE pipe.

Regarding the polybutene pipe, a polybutene “Burelon P5050” manufactured by Mitsui Petrochemical was obtained, and the pipe was manufactured in the same manner as in Example 1.

Example 4 TPE-2 (hydrogenated styrene /
Isoprene Block Polymer, Kuraray “Septon 2
023 ", bound styrene: 13%), PP, POX, D
VB is calculated as TPE-2 / PP / POX / DVB = 29.7 /
Using a blender at a weight ratio of 69.3 / 0.3 / 0.7, the mixture was mixed in the same manner as in Example 1, and dynamically crosslinked in the same manner as in Example 1 to obtain a PP-based resin composition TPV-2. The Shore D hardness was 60. Using the obtained TPV-2, pipe extrusion was performed with the same 50 mm extruder as in Example 1.

Table 1 shows the evaluation results of Examples 1 to 4 and Comparative Examples 1 and 2. In addition, "NB" in a table | surface shows that the measurement sample did not lead to destruction.

[0075]

[Table 1]

[0076]

The pipe material of the present invention has excellent thermal characteristics (high-temperature characteristics and low-temperature characteristics) and has sufficient flexibility, so that it is possible to freely design the pipe hardness and to extrude the pipe. Excellent in nature. Furthermore, since it is a thermoplastic material, it has recyclability. Therefore, according to the present invention, a hot water supply and a water supply pipe which can be sufficiently applied to use in cold regions and can be recycled are easily provided, and the role of the present invention in the industrial world is great.

[Brief description of the drawings]

FIG. 1 is a photograph showing the morphology of a pipe material obtained in Example 1 of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 25/04 C08L 25/04 // B29C 47/20 B29C 47/20 Z B29K 9:06 B29K 9:06 19:00 19:00 23:00 23:00 105: 24 105: 24 B29L 23:00 B29L 23:00 (72) Inventor Sueki 2-595, Nakanosecho, Nobeoka-shi, Miyazaki Prefecture Asahi Organic Materials F term (reference) in Industrial Co., Ltd. BB12X BB14X BB15W BB15X BC02W BC05W BP01W EK016 EK026 EK036 EK046 EK056 EK066 EK086 FD010 FD020 FD146 GL00

Claims (6)

[Claims] 1. A ratio of (A) / (B) = 5/95 to 70/30 by weight ratio of at least (A) a partially or completely crosslinked rubbery polymer and (B) a polypropylene resin. Wherein the rubber-like polymer and the polypropylene-based resin are a polypropylene-based resin composition having a phase-separated structure. 2. The polypropylene resin pipe material according to claim 1, wherein the rubbery polymer as the component (A) is at least one selected from olefin elastomers and styrene elastomers. 3. The polypropylene resin according to claim 2, wherein the olefin elastomer is an ethylene / α-olefin copolymer containing ethylene as a monomer component and an α-olefin having 3 to 20 carbon atoms as a main component. Pipe material. 4. The polypropylene resin pipe material according to claim 2, wherein the styrene elastomer is at least one selected from an aromatic vinyl / conjugated diene copolymer and a hydrogenated aromatic vinyl / conjugated diene copolymer. . 5. A resin composition produced by subjecting the pipe material to dynamic crosslinking of an uncrosslinked rubber-like polymer and a polypropylene resin in the coexistence of a crosslinking agent, or a polypropylene composition added to the resin composition. The polypropylene resin pipe material according to any one of claims 1 to 4, which is a resin composition obtained by mixing a resin. 6. The polypropylene resin pipe material according to claim 1, which has a Shore D hardness of 50 to 75.