JP2020186806A - Heat-resistant transparent joint - Google Patents

Abstract

To provide a large-diameter, heat-resistant transparent joint that suppresses burns occurring during molding.SOLUTION: A heat-resistant transparent joint has a body part 10 that has a channel inside and has two or more openings formed therein, and reception parts 11 surrounding the edges of the openings of the body part. The body part 10 and the reception parts 11 are composed of a resin composition that contains vinyl chloride resin with a chlorine content of 56.6-58.2 mass%. At least one 11a (11b) of the reception parts 11 allows an end of a tube with a nominal diameter of 75-100 to be inserted thereto.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat resistant transparent joint.

A piping system that combines a heat-resistant pipe and a drainage joint that uses heat-resistant rigid vinyl chloride resin used for hot water supply is a high-temperature drainage that flows from kitchen drainage, dishwashers, electric water heaters, etc. (See, for example, Non-Patent Document 1).

"Eslon HTDV Fitting Catalog Revised 7th Edition 3rd Printing", Sekisui Chemical Co., Ltd., October 2018

When forming a large-diameter heat-resistant transparent joint having a nominal diameter of 75 or more, a phenomenon called discoloration may occur in which the joint turns yellow.
However, in the past, measures to reduce discoloration have not been sufficiently taken.

Therefore, an object of the present invention is to provide a large-diameter heat-resistant transparent joint in which discoloration generated during molding is reduced.

The above problem is solved by the following configuration.
[1] A main body having a flow path inside and having two or more openings formed therein, and a receiving portion surrounding the peripheral edge of the opening of the main body are provided.
The main body portion and the receiving portion are made of a resin composition containing a vinyl chloride resin and having a chlorine content of 56.6 to 58.2% by mass.
At least one of the receiving portions is a heat-resistant transparent joint into which an end portion of a pipe having a nominal diameter of 75 to 100 can be inserted.
[2] The heat-resistant transparent joint according to [1], wherein the resin composition contains a tin-based stabilizer.
[3] The heat-resistant transparent joint according to [2], wherein the content of the tin-based stabilizer is 4.0 to 10.0 parts by mass with respect to 100 parts by mass of the vinyl chloride-based resin.
[4] The heat-resistant transparent joint according to [2] or [3], wherein the tin-based stabilizer is an octyl tin mercapto stabilizer.

According to the present invention, it is possible to provide a heat-resistant transparent joint having a large diameter with reduced discoloration generated during molding.

FIG. 1 is a side view showing a first embodiment of the heat-resistant transparent joint of the present invention. FIG. 2 is a vertical cross-sectional view of the heat-resistant transparent joint shown in FIG. FIG. 3 is a side view showing a second embodiment of the heat-resistant transparent joint of the present invention. FIG. 4 is a vertical cross-sectional view of the heat-resistant transparent joint shown in FIG.

In the present specification, the numerical range represented by using "~" shall include the numerical values at both ends thereof.
In the present specification, "transparent" means that the inside of the joint can be visually recognized from the outside of the joint with the naked eye. More specifically, it means that the haze value measured according to JIS K 7136: 2000 "How to determine the haze of a plastic-transparent material" is 20 to 80.

[Heat-resistant transparent fitting]
The heat-resistant transparent joint of the present invention includes a main body portion having a flow path inside and having two or more openings formed therein, and a receiving portion surrounding the peripheral edge of the opening of the main body portion, and the main body portion and the receiving portion. The part comprises a resin composition containing a vinyl chloride resin and having a chlorine content of 56.6 to 58.2% by mass.
At least one of the receiving portions is capable of inserting the end portion of a pipe having a nominal diameter of 75 to 100.

<First Embodiment>
Hereinafter, the first embodiment of the heat-resistant transparent joint of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a side view showing a first embodiment of the heat-resistant transparent joint of the present invention, and FIG. 2 is a vertical cross-sectional view of the heat-resistant transparent joint shown in FIG.
As shown in FIGS. 1 and 2, the heat-resistant transparent joint 1 according to the first embodiment of the present invention uses an elbow used for connecting a drain pipe as an example. The heat-resistant transparent joint 1 includes a main body portion 10 having a flow path 14 that bends inside and having a first opening 12a and a second opening 12b at both ends. The heat-resistant transparent joint 1 has a cylindrical first receiving portion 11a surrounding the peripheral edge of the first opening 12a of the main body portion 10 and a cylindrical second receiving portion 11a surrounding the peripheral edge of the second opening 12b of the main body portion 10. The receiving unit 11b is provided. The main body portion 10, the first receiving portion 11a, and the second receiving portion 11b are integrally formed.

A pipe member having a diameter substantially the same as the inner diameter of the receiving portion 11 is inserted into the receiving portion 11. At least one of the receiving portions 11 can be inserted into the end of a pipe having a nominal diameter of 75 to 100. The inner diameter of the opening 13 of the receiving portion is larger than the inner diameter of the opening 12 of the main body 10.

From the viewpoint of improving visibility when the tube is inserted, it is preferable that the receiving portion 11 has a uniform thickness.
The thickness of the receiving portion 11 is not particularly limited, but is preferably 2 to 8 mm, more preferably 3 to 5 mm, for example. When the thickness of the receiving portion 11 is within this range, the strength of the receiving portion 11 can be easily maintained and the visibility of the receiving portion 11 can be easily improved.
The thickness of the main body 10 is not particularly limited, but is preferably 2 to 8 mm, more preferably 3 to 6 mm, for example. When the thickness of the main body 10 is within this range, it is easy to maintain the strength of the main body 10 and to reduce the weight of the heat-resistant transparent joint 1.

In FIGS. 1 and 2, Y indicates the position of the gate for introducing the resin composition into the cavity (space) of the injection molding die used when the heat-resistant transparent joint 1 is injection-molded. A gate mark is formed at a position corresponding to the gate.
When the gate position is Y of the main body portion 10, the distance from the gate to the receiving portion 11 is equal, and the variation of the receiving portion 11 can be further reduced. Y may be located anywhere in the main body 10 as long as the distances from the first receiving portion 11a and the second receiving portion 11b are equal.

<Second embodiment>
Hereinafter, a second embodiment of the heat-resistant transparent joint of the present invention will be described with reference to FIGS. 3 and 4.
FIG. 3 is a side view showing a second embodiment of the heat-resistant transparent joint of the present invention, and FIG. 4 is a vertical sectional view of the heat-resistant transparent joint shown in FIG.
As shown in FIGS. 3 and 4, the heat-resistant transparent joint 2 according to the second embodiment of the present invention exemplifies cheese used for connecting a drain pipe. The heat-resistant transparent joint 2 has a main body portion 20 having a flow path 24 that branches or merges inside, and has a first opening 22a, a second opening 22b, and a third opening 22c at the ends. To be equipped. The heat-resistant transparent joint 2 has a cylindrical first receiving portion 21a that surrounds the edge of the first opening 22a of the main body 20, and a cylindrical shape that surrounds the edge of the second opening 22b of the main body 20. A second receiving portion 21b and a cylindrical third receiving portion 21c surrounding the edge of the third opening 22c of the main body portion 20 are provided. The main body portion 20, the first receiving portion 21a, the second receiving portion 21b, and the third receiving portion 21c are integrally formed.
A pipe member having a diameter substantially the same as the inner diameter of the receiving portion 21 is inserted into the receiving portion 21. One or more of the receiving portions 21 can be inserted into the end portion of a pipe having a nominal diameter of 75 to 100. The inner diameter of the opening 23 of the receiving portion is larger than the inner diameter of the opening 22 of the main body 20.

Of the three openings 22 of the main body 20, two are circular in coaxial with the first tube shaft O1.
Further, two of the three receiving portions 21 are tubular, coaxial with the first tube shaft O1. The receiving portion on one end side of the first pipe shaft O1 is the first receiving portion 21a, and the receiving portion on the other end side is the second receiving portion 21b. The remaining one is a tubular shape coaxial with the second tube shaft O2 and is a third receiving portion 21c.

From the viewpoint of improving visibility when the tube is inserted, it is preferable that the receiving portion 21 has a uniform thickness.
The thickness of the receiving portion 21 is not particularly limited, but is preferably 2 to 8 mm, more preferably 3 to 5 mm, for example. When the thickness of the receiving portion 21 is within this range, the strength of the receiving portion 21 can be easily maintained and the visibility of the receiving portion 21 can be easily improved.
The thickness of the main body 20 is not particularly limited, but is preferably 2 to 8 mm, more preferably 3 to 6 mm, for example. When the thickness of the main body 20 is within this range, it is easy to maintain the strength of the main body 20 and to reduce the weight of the heat-resistant transparent joint 2.

In FIGS. 3 and 4, Y indicates the position of the gate for introducing the resin composition into the cavity (space) of the injection molding die used when the heat-resistant transparent joint 2 is injection-molded. A gate mark is formed at a position corresponding to the gate.
When the gate position is Y of the main body portion 20, the distance from the gate to the receiving portion 21 is equal, and the variation of the receiving portion 21 can be further reduced. The position of Y is an example, and if Y is at a position where the distances from the first receiving portion 21a, the second receiving portion 21b, and the third receiving portion 21c are equal, it is located anywhere in the main body portion 20. May be good.

<Resin composition>
The main body portion 10 (20) and the receiving portion 11 (21) of the heat-resistant transparent joint 1 (2) are made of a resin composition containing a vinyl chloride resin and having a chlorine content of 56.6 to 58.2% by mass. ..
The heat-resistant transparent joint 1 (2) may have a single-layer structure in which the entire heat-resistant transparent joint 1 (2) is made of a resin composition, or may be a laminated structure made of a plurality of layers.

Examples of the vinyl chloride resin contained in the resin composition include a homopolymer of a vinyl chloride monomer; a copolymer of a vinyl chloride monomer and another monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer. Examples thereof include a graft copolymer obtained by graft-copolymerizing a vinyl chloride monomer with a polymer other than a vinyl chloride resin.
The vinyl chloride resin may be further chlorinated. Examples of the chlorination method for the vinyl chloride resin include a thermal chlorination method and a photochlorination method.

Examples of other monomers having an unsaturated bond copolymerizable with the vinyl chloride monomer include α-olefins such as ethylene, propylene and butylene; vinyl esters such as vinyl acetate and vinyl propionate; butyl vinyl ether and cetyl. Vinyl ethers such as vinyl ethers; (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl acrylate; aromatic vinyls such as styrene and α-methylstyrene; N-phenylmaleimide, N- Examples thereof include N-substituted maleimides such as cyclohexyl maleimide. As the other monomer, one type may be used alone, or two or more types may be used in combination.

Examples of the polymer for graft-copolymerizing the vinyl chloride monomer include ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butyl acrylate-1. Examples thereof include carbon oxide copolymers, ethylene-methylmethacrylate copolymers, ethylene-propylene copolymers, acrylonitrile-butadiene copolymers, polyurethanes, chlorinated polyethylenes and chlorinated polypropylenes. One of these polymers may be used alone, or two or more of these polymers may be used in combination.

The vinyl chloride resin may be crosslinked. Examples of the method for cross-linking the vinyl chloride resin include a method of adding a cross-linking agent and a peroxide, a method of irradiating an electron beam, and a method of using a water-crosslinkable material.

As the vinyl chloride resin, one type may be used alone, or two or more types may be used in combination.

The mass average molecular weight of the vinyl chloride resin is preferably 37500 to 70000, more preferably 37500 to 44000.
The mass average molecular weight is a value measured by gel permeation chromatography using polyethylene glycol as a standard substance.
When the mass average molecular weight of the vinyl chloride resin is within this range, the mechanical strength can be further increased and sufficient moldability can be ensured.

When the vinyl chloride resin is polyvinyl chloride, the degree of polymerization of polyvinyl chloride is preferably 600 to 800, more preferably 600 to 700.
The average degree of polymerization can be calculated by dividing the mass average molecular weight by the molecular weight of chloroethylene.
When the average degree of polymerization of polyvinyl chloride is within this range, the mechanical strength can be further increased and sufficient moldability can be ensured.

The resin composition may contain a thermoplastic resin other than the vinyl chloride resin. Examples of thermoplastic resins other than vinyl chloride resins include polyethylene, polypropylene, polystyrene, polybutene, chlorinated polyethylene, ethylene-propylene copolymer, ethylene-ethylacrylate copolymer, polyethylene terephthalate, ABS resin, acrylic resin and the like. Can be mentioned. One of these thermoplastic resins may be used alone, or two or more thereof may be used in combination.
In the resin composition, the content of the vinyl chloride resin with respect to the total mass of the vinyl chloride resin and the thermoplastic resin other than the vinyl chloride resin is preferably 70 to 100% by mass, more preferably 70 to 80% by mass. , 70-75% by mass is more preferable.

The chlorine content of the resin composition is 56.6 to 58.2% by mass, preferably 57 to 58% by mass, and more preferably 57.2 to 57.8% by mass. When the chlorine content of the resin composition is within this range, discoloration during molding can be suppressed.
The chlorine content of the resin composition was measured by flask burning / titration based on JIS K 7229: 1995 "Method for quantifying chlorine in chlorine-containing resin".

(Stabilizer)
The resin composition preferably contains a stabilizer for the purpose of suppressing thermal decomposition of the vinyl chloride resin. Examples of the stabilizer include a tin-based stabilizer, a Ca-Zn-based stabilizer, a higher fatty acid metal salt, and the like. As the stabilizer, one type may be used alone, or two or more types may be used in combination. However, lead-based stabilizers are excluded.
Examples of the tin-based stabilizer include mercaptides such as dibutyltin mercapto, dioctyltin mercapto, and dimethyltin mercapto; malates such as dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, and dioctyltin malate polymer; dibutyl. Examples thereof include carboxylates such as tin mercaptodibutyl tin laurate and dibutyltin laurate polymer. From the viewpoint of ensuring transparency, the tin-based stabilizer is preferably a mercapto-based compound. For example, dibutyl tin mercaptan, dioctyl tin mercaptan and the like can be mentioned. As the tin-based stabilizer, one type may be used alone, or two or more types may be used in combination.
The Ca-Zn-based stabilizer is a mixture of a fatty acid salt of calcium and a fatty acid salt of zinc. Examples of fatty acids include behenic acid, stearic acid, lauric acid, oleic acid, palmitic acid, ricinoleic acid, benzoic acid and the like. As the Ca—Zn-based stabilizer, one type may be used alone, or two or more types may be used in combination.
Examples of the higher fatty acid metal salt include lithium stearate, magnesium stearate, calcium stearate, calcium laurate, calcium ricinolate, strontium stearate, barium stearate, barium laurate, barium ricinolate, cadmium stearate, and cadmium laurate. , Cadmium ricinolate, cadmium naphthenate, cadmium 2-ethylhexoate, zinc stearate, zinc laurate, zinc ricinolate, zinc 2-ethylhexoate, lead stearate, lead dibasic stearate, lead naphthenate, etc. Be done. One type of higher fatty acid metal salt may be used alone, or two or more types may be used in combination.
Among these, tin-based stabilizers are preferable. From the viewpoint of further enhancing the thermal stability of the vinyl chloride resin and improving the processability, it is preferable to use two or more tin stabilizers in combination.

The content of the stabilizer is not particularly limited, but is preferably 1.0 to 10.0 parts by mass and more preferably 2.0 to 5.0 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. When the content of the stabilizer is within this range, when the stabilizer is within the above range, discoloration during molding can be further suppressed.

(Additive)
The resin composition contains a modifier, a lubricant, a processing aid, a colorant, an inorganic flame retardant, an impact modifier, a heat resistance improver, an antioxidant, and a heat stabilization aid as long as the effects of the present invention are not impaired. Additives such as agents, light stabilizers, UV absorbers, plasticizers, thermoplastic elastomers and the like may be included.
One of these additives (arbitrary components) may be used alone, or two or more thereof may be used in combination.

The content of the optional component is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less with respect to 100 parts by mass of the vinyl chloride resin.

[Manufacturing method of heat-resistant transparent joint]
The heat-resistant transparent joint 1 (2) is manufactured by injection molding.
For example, the heat-resistant transparent joint 1 (2) is obtained by heating and melting the resin composition, injecting it into a mold, heating it at an arbitrary temperature for an arbitrary time, and cooling it at an arbitrary temperature for an arbitrary time.

In the injection molding machine, the temperature (molding temperature) of the resin composition immediately before being injected into the mold is preferably 170 to 190 ° C, more preferably 180 to 190 ° C. When the molding temperature is within the above range, the vinyl chloride resin is sufficiently melted while suppressing thermal decomposition, and good fluidity of the resin composition can be obtained.
The time for molding with a mold is preferably 1 to 5 minutes. Within this range, discoloration in the screw can be suppressed.

Although the first embodiment and the second embodiment of the heat-resistant transparent joint of the present invention have been described in detail above, the present invention is not limited to the above-described embodiment and does not deviate from the gist thereof. Can be changed as appropriate.

The number of openings formed in the main body of the heat-resistant transparent joint is not limited to two or three, and may be four or five or more. The inner diameter of the opening may be the same as or different from the inner diameter of the other openings.
The cross section of the main body of the resin pipe joint cut along a plane perpendicular to the pipe axis direction may be circular in a plan view, elliptical in a plan view, or polygon in a plan view.
Examples of the shape of the resin pipe joint include nipples, nipples with different diameters (reducers), cloths, valve sockets, and the like, in addition to the above elbows and cheeses.

As described above, the heat-resistant transparent joint of the present invention is a large-diameter heat-resistant transparent joint in which discoloration caused during molding is reduced. Since the discoloration is reduced, the receiving portion of the heat-resistant transparent joint of the present invention is transparent, the inserted state of the pipe inside the joint can be confirmed, and the pipe is fixed to the receiving portion of the joint. It can be easily and surely made visible.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples, and various modifications are possible as long as the gist of the present invention is not changed.

[Example 1]
100 parts by mass of vinyl chloride resin (vinyl chloride, Sekisui CPVC HA-27H, manufactured by Tokuyama Sekisui Kogyo Co., Ltd.), 4.0 parts by mass of stabilizer (Dioctyl tin mercapto, ONZ-142AF, manufactured by Nitto Kasei Co., Ltd.), After blending 9.6 parts by mass of optional components (modifier, lubricant, processing aid, colorant), the resin composition is mixed by stirring using a side shell mixer (manufactured by Kawada Kogyo Co., Ltd.) with an internal volume of 200 L. I got something. The composition of the resin composition is shown in Table 1.
The obtained resin composition was injection-molded to produce a cheese (tea) -shaped joint having the shape shown in FIG. The receiving portion has a size that allows the end of a pipe having a nominal diameter of 75 to 100 to be inserted. The molding temperature was 175 ° C., the mold temperature was 20 ° C., and the molding time was 100 seconds.
The obtained joint had an opaque white body and a transparent yellow receiving part.
The following tests were performed on the obtained joints.

<Chlorine content>
The chlorine content (unit: mass%) was measured by flask burning / titration based on JIS K 7229: 1995 "Method for quantifying chlorine in chlorine-containing resin".
The measurement results are shown in Table 1.

<Transparency>
The haze value of the receiving part of the manufactured joint was measured according to JIS K 7135: 2000 “Plastic-How to determine the haze of transparent material”.
The transparency of the receiving part of the joint was evaluated according to the following criteria.
◯: Haze value is 20 to 80 ×: Haze value is more than 80

<Heat resistance>
The Vicat softening temperature of the manufactured joint was measured according to JIS K 7206: 2016 "Plastic-Thermoplastic Plastic-How to Obtain the Vicat Softening Temperature (VST)".
The heat resistance of the joint was evaluated according to the following criteria.
◯: Vicat softening temperature is 90 ° C. or higher ×: Vicat softening temperature is less than 90 ° C. The evaluation results are shown in Table 1.

<Burning resistance>
The appearance of the manufactured joint was visually observed to confirm the presence or absence of discoloration and the presence or absence of discoloration.
The burn resistance of the joint was evaluated according to the following criteria.
◯: No burns ×: Burns The evaluation results are shown in Table 1.

<Comprehensive evaluation>
Comprehensive evaluation was performed according to the following criteria based on heat resistance and burn resistance.
◯: All evaluations of transparency, heat resistance and burn resistance are “○” ×: Evaluation results of one or more of the evaluations of transparency, heat resistance and burn resistance are “×” Table 1 Shown in.

[Example 2]
A joint was manufactured in the same manner as in Example 1 except that chlorinated vinyl chloride (Sekisui CPVC HA-27F, manufactured by Tokuyama Sekisui Kogyo Co., Ltd.) was used as the vinyl chloride resin, and transparency, heat resistance and resistance were obtained. The discoloration was evaluated and a comprehensive evaluation was performed. The evaluation results are shown in Table 1.

[Comparative Example 1]
A joint was manufactured in the same manner as in Example 1 except that chlorinated vinyl chloride (Sekisui CPVC HA-27K, manufactured by Tokuyama Sekisui Kogyo Co., Ltd.) was used as the vinyl chloride resin, and transparency, heat resistance and resistance were obtained. The discoloration was evaluated and a comprehensive evaluation was performed. The evaluation results are shown in Table 1.

In Table 1, vinyl chloride resins, stabilizers and compounding agents are as follows.
-Vinyl chloride resin H: Chlorinated vinyl chloride (Sekisui CPVC HA-27H, manufactured by Tokuyama Sekisui Kogyo Co., Ltd., chlorination degree 65.5% by mass)
F: Chlorinated vinyl chloride (Sekisui CPVC HA-27F, manufactured by Tokuyama Sekisui Kogyo Co., Ltd., chlorination degree 64.5% by mass)
K: Vinyl chloride chlorinated (Sekisui CPVC HA-27K, manufactured by Tokuyama Sekisui Kogyo Co., Ltd., degree of chlorination 66.5% by mass)
・ Stabilizer Dioctyl tin mercapto (ONZ-142AF, manufactured by Nitto Kasei Co., Ltd.)

[Explanation of results]
The joints of Examples 1 and 2 satisfied the required levels of heat resistance and burn resistance, and the overall evaluation was also good (◯).
The joint of Comparative Example 1 had sufficient heat resistance (evaluation: 〇), but had insufficient transparency and burn resistance (evaluation: ×), and the overall evaluation was unacceptable (×).
According to the present invention, it is possible to provide a large-diameter heat-resistant transparent joint in which discoloration caused during molding is reduced.

1, 2 Heat-resistant transparent joints 10, 20 Main body 11, 21 Receiving part 11a, 21a First receiving part 11b, 21b Second receiving part 21c Third receiving part 12, 22 Opening 12a, 22a First opening Part 12b, 22b Second opening 22c Third opening 13, 23 Receiving part opening 13a, 23a Receiving part first opening 13b, 23b Receiving part second opening 23c Receiving part first Openings 14 and 24 Flow path O1 First pipe shaft O2 Second pipe shaft

Claims (4)

A main body having a flow path inside and having two or more openings formed therein, and a receiving portion surrounding the peripheral edge of the opening of the main body are provided.
The main body portion and the receiving portion are made of a resin composition containing a vinyl chloride resin and having a chlorine content of 56.6 to 58.2% by mass.
At least one of the receiving portions is a heat-resistant transparent joint into which an end portion of a pipe having a nominal diameter of 75 to 100 can be inserted. The heat-resistant transparent joint according to claim 1, wherein the resin composition contains a tin-based stabilizer. The heat-resistant transparent joint according to claim 2, wherein the content of the tin-based stabilizer is 4.0 to 10.0 parts by mass with respect to 100 parts by mass of the vinyl chloride-based resin. The heat-resistant transparent joint according to claim 2 or 3, wherein the tin-based stabilizer is an octyl tin mercapto stabilizer.

Images