JP2005272721A - Hot-melt composition and water-proof connector using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hot-melt composition that can favorably adhere non-polar polymers such as a polyolefin material or polar polymers such as PBT or PA and can be used for a hot-melt adhesive, and provide a water-proof connecter using the same. <P>SOLUTION: The water-proof connecter 1 comprises a plurality of electric wires 4 formed by covering core wire with a non-polar polymer, and a plurality of connection terminals 5 connected to a plurality of these electric wires 4, a connector housing 3 that is made of a polar polymer and has a terminal-receiving room 2 for receiving the terminals 5 inside, and a mold resin 6 that prevents moisture from invading into the terminal-receiving room 2 and encapsulates the connection parts between the electric wires 4 and the connection terminals 5 in the inside of the housing 3. The mold resin is mainly composed of a maleic acid-modified olefinic resin, a 9C hydrogenated petroleum resin, an amorphous polyolefin and styrene-ethylene-propylene-styrene rubber. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hot melt composition used for a hot melt adhesive, a hot melt sealing agent, and the like, and a waterproof connector using the same.

  When using covered wires as automotive assembled wires (wire harnesses), a waterproof connector in which the inside of the connector housing is sealed with hot-melt resin in order to ensure the waterproofness of the connection portion between the wires and connection terminals in the connector housing Has been proposed (Patent Document 1). In general, connectors are made of polyvinyl chloride (hereinafter referred to as “PVC”) in which terminals are crimped on a connector housing made of polybutylene terephthalate (hereinafter referred to as “PBT”) resin, polyamide (hereinafter referred to as “PA”) resin, or the like. Insert and use an automotive electric wire (AV wire) with insulation coating. In order to realize the above-described waterproof connector, it is necessary to use a hot-melt resin that exhibits good adhesive properties for both PBT, PA, and PVC. Conventionally, a polyamide-based hot melt resin has been proposed as such a hot melt resin (Patent Document 1).

  By the way, in recent years, environmental measures have been regarded as important, and so-called eco electric wires using a coating that does not use heavy metals such as lead instead of polyvinyl chloride (PVC), for example, a polyolefin-based non-halogen material, have been adopted. However, since the polyolefin-based non-halogen material is a nonpolar polymer and is generally referred to as a difficult-to-adhere material, there is a problem in that it cannot be satisfactorily bonded depending on the polyamide hot-melt adhesive that is usually used. .

  On the other hand, for example, Patent Document 2 describes a hot-melt adhesive having good adhesion to a polyolefin material, but this hot-melt adhesive dissolves instead of having good adhesion to a polyolefin material. There is a problem that the adhesiveness parameter does not have sufficient adhesion to PBT or PA having a large separation parameter.

Japanese Patent Laid-Open No. 2002-93515, paragraph 0029, FIG. JP 2001-139911 A

Accordingly, the present invention provides a hot melt composition used for a hot melt adhesive or the like that can satisfactorily bond both non-polar polymers such as polyolefin-based materials and polar polymers such as PBT and PA. Is the first purpose.
Moreover, this invention makes it the 2nd objective to provide the waterproof connector which improved waterproofness using such a hot-melt composition as mold resin.

  In order to achieve the above first object, the hot melt composition according to the present invention is mainly composed of maleic acid-modified polyolefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin and styrene ethylene propylene styrene rubber.

  In order to achieve the second object, the waterproof connector according to the present invention includes a plurality of electric wires in which a core wire is covered with an insulating coating made of a nonpolar polymer, and a plurality of electric wires connected to the plurality of electric wires. A connector housing made of a polar polymer having a terminal housing hole for housing the plurality of connection terminals therein, and preventing the ingress of moisture into the terminal housing hole of the connector housing and the wire and the connection terminal; And a molded resin that seals the connecting portion of the connector housing inside the connector housing, wherein the mold resin is mainly maleic acid-modified polyolefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin, and styrene ethylene propylene styrene rubber. It is characterized by being a component.

According to the hot melt composition of the present invention, a non-polar polymer such as a polyolefin-based material and PBT are formed by using maleic acid-modified polyolefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin, and styrene ethylene propylene styrene rubber as main components. It is possible to bond both polar polymers such as PA and PA well.
Moreover, according to the waterproof connector which concerns on this invention, waterproofness can be improved by using such a hot-melt composition as mold resin.

  In the present invention, the maleic acid-modified polyolefin resin gives the mold resin or hot melt composition according to the present invention polarity. By adding this resin to the mold resin or hot melt composition according to the present invention, it is possible to satisfactorily adhere to PBT and PA which are polar polymers and whose solubility parameters are far from those of olefins. Become. In other words, maleic acid-modified polyolefins contribute greatly to the development of adhesion to polar polymers such as PBT and PA, which are difficult to bond with polyolefin hot melt compositions, while maintaining adhesion to olefinic non-halogen materials. is there. Further, the C9 hydrogenated petroleum resin has a function of developing tack (initial adhesive strength) by its addition, and this function can greatly contribute to the improvement of adhesion to polar polymers such as PBT and PA. Furthermore, the C9 hydrogenated petroleum resin can be compatible with materials such as maleic acid-modified polyolefin to reduce the melt viscosity of the hot melt composition, improve the filling workability, and exhibit the wettability to the material. .

  In the mold resin or hot melt composition according to the present invention, the C9 hydrogenated petroleum resin and the amorphous polyolefin are olefin-based base materials, and their solubility parameters are close to those of olefin-based non-halogen materials. Adhesion to non-halogen materials can be improved. Styrene ethylene propylene styrene rubber improves thermal shock and the like.

  In the hot melt composition according to the present invention, the maleic acid-modified polyolefin resin is 5 to 25% by weight, the C9 hydrogenated petroleum resin is 15 to 50% by weight, the amorphous polyolefin is 30 to 55% by weight, and styrene ethylene propylene The styrene rubber is preferably 1 to 20% by weight, particularly 10 to 20% by weight of the maleic acid-modified polyolefin resin, 35 to 40% by weight of the C9 hydrogenated petroleum resin, and 35 to 50% by weight of the amorphous polyolefin. More preferably, the styrene ethylene propylene styrene rubber is 5 to 15% by weight.

  The maleic acid-modified polyolefin resin is obtained by modifying a polyolefin resin with maleic acid or maleic anhydride, and this modification treatment can be performed by a conventionally known method. For example, it can be obtained by adding a maleic acid or maleic anhydride to a polyolefin resin together with a peroxide and kneading them using a single-screw kneading extruder or a twin-screw kneading extruder and performing a graft reaction. The maleic acid modification rate is preferably 1 to 10% by weight in terms of maleic acid groups. Examples of the maleic acid-modified polyolefin resin used in the hot melt composition according to the present invention include maleic acid-modified polypropylene and maleic acid-modified polyethylene.

  C9 hydrogenated petroleum resin is C9 petroleum resin obtained by partially or fully hydrogenating C9 petroleum resin obtained by singly or copolymerizing styrene, α-methylstyrene, vinyltoluene, and indene, which are C9 fractions of petroleum. The hydrogenation can be performed by a conventionally known method. The degree of hydrogenation is preferably a completely hydrogenated C9 petroleum resin in view of compatibility with other materials, weather resistance, heat resistance and color tone. Examples of the C9 hydrogenated petroleum resin used in the hot melt composition according to the present invention include Ligalite R type manufactured by Eastman Chemical Co., Alcon P type and M type manufactured by Arakawa Chemical Co., Ltd.

  The amorphous polyolefin is an amorphous olefin polymer obtained by copolymerizing propylene alone or propylene and another olefin, and those having a molecular weight of about 1000 to 100,000 are suitable. Examples of the amorphous polyolefin used in the hot melt composition according to the present invention include amorphous polypropylene such as Chisso Bistack, Sanyo Chemical Co., Ltd. Biscol, Degussa Bestplast.

  The hot melt composition according to the present invention can be obtained by mixing these maleic acid-modified olefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin, and styrene ethylene propylene styrene rubber. The mixing apparatus includes a Banbury mixer, a kneader. An extruder or the like is used.

  Next, examples of the hot melt composition according to the present invention will be described. First, the hot melt compositions according to Examples 1 to 5 were obtained by melt-kneading resins 1 to 5 shown in Table 1 at 200 ° C. using a biaxial kneader. In Examples and Comparative Examples, the melt viscosity of the hot melt composition was measured at 180 ° C. using a Brookfield viscometer based on JIS K 6862, and the softening point was measured based on JIS K 6863. did.

樹脂１：マレイン酸変性ポリプロピレン（ユニロイヤルケミカ社製、ポリボンド３２００）
樹脂２：マレイン酸変性ポリエチレン（日本製紙ケミカル社製、アウロ−レン150Ｓ）
樹脂３：Ｃ９水添石油樹脂（荒川化学工業社製、アルコンＰ-140）
樹脂４：アモルファスポリプロピレン（デグサ社製、ベストプラスト８２８）
樹脂５：スチレンエチレンプロピレンスチレンゴム （クラレ社製、セプトン
2002）

Resin 1: Maleic acid-modified polypropylene (manufactured by Uniroyal Chemica, polybond 3200)
Resin 2: Maleic acid-modified polyethylene (Nippon Paper Chemical Co., Ltd., Aurolen 150S)
Resin 3: C9 hydrogenated petroleum resin (Arakawa Chemical Industries, Alcon P-140)
Resin 4: Amorphous polypropylene (Degussa, Best Plast 828)
Resin 5: Styrene ethylene propylene styrene rubber (Kuraray, Septon
2002)

Next, the waterproof connector 1 shown in FIG.1 and FIG.2 was formed in the resin mold part using the hot-melt composition which concerns on these Examples 1 thru | or 5. 1 is an external perspective view, and FIG. 2 is an AA ′ cross-sectional view of FIG.
The waterproof connector 1 is housed in a connector housing 3 having a plurality of independent terminal housing chambers 2 formed therein, and in the terminal housing chamber 2 of the connector housing 3. It comprises a plurality of fixed connection terminals 5 and a mold resin 6 using the hot melt composition according to Examples 1 to 5 for sealing the inside of the terminal accommodating chamber 2.

  A terminal insertion port 7 communicating with the terminal accommodating chamber 2 is formed on the base end side of the connector housing 3, and the connection terminal 5 is inserted into the terminal accommodating chamber 2 from the terminal insertion port 7. A terminal projecting port 8 that gradually narrows as the opening becomes the front end side is provided at the distal end side of the terminal accommodating chamber 2, and the distal end of the connection terminal 5 projects from the terminal accommodating chamber 2 through the terminal projecting port 8. To do. A lance 9 projects from the inner peripheral wall of the terminal accommodating chamber 2 obliquely forward. The lance 9 prevents the connection terminal 5 from coming out backward. On the distal end side of the connector housing 3, a fitting peripheral wall 10 that protrudes from a mating connector (not shown) and surrounds the distal end of the connection terminal 5 is provided. When the mold resin 6 is filled in the terminal accommodating chamber 2, a hole for fitting with the tip of the connection terminal 5 is formed inside the fitting peripheral wall 10 in order to prevent the mold resin 6 from protruding from the terminal protrusion 8. It can be manufactured by inserting the formed jig, pressing the terminal protruding port 8 from the opening side, and filling the mold resin 6 from the terminal inserting port 7 side.

  Here, the insulation coating of the electric wire 4 is made of a nonpolar polymer such as polyethylene, and the connector housing 3 is made of a resin molded member of a polar polymer such as PBT. Actually, when the electric wire 4 and the connector housing 3 were bonded by the mold resin 6 using the hot melt compositions according to Examples 1 to 5, these materials could be bonded well to each other.

Experimental example 1
Next, in order to verify the adhesiveness of the hot melt compositions according to Examples 1 to 5 with respect to polyethylene, which is a nonpolar polymer, a peel test was performed according to JIS K 6854 (T-type test: peel pieces are flexible materials). Based on. Peel test 1 was conducted in the initial state, peel test 2 was conducted at room temperature after standing in a 120 ° C. atmosphere for 24 hours, and peel test 3 was conducted in a −40 ° C. atmosphere. The peeling test 4 was performed in a state after 1 hour of boiling in water. These results are shown in Table 2.

  Next, as Comparative Example 1, a polyester hot melt composition, as Comparative Example 2, a polyamide hot melt composition (Telmelt 865, manufactured by TRL), and as Comparative Example 3, a polyolefin hot melt composition (trade name: Macromelt Q5353 (Manufactured by Henkel) and a polyamide hot melt composition (RNA-254, manufactured by Asahi Chemical Synthesis Co., Ltd.) was prepared as Comparative Example 4, and these were also peeled in the same manner as the hot melt compositions according to Examples 1 to 5. Was done. The results are shown in Table 3.

  As is clear from Tables 2 and 3, the hot melt compositions according to Examples 1 to 5 have better adhesion to nonpolar polymers than the hot melt compositions according to Comparative Examples 1 to 4. I understand.

Experimental example 2
Next, in order to verify the adhesion of the hot melt compositions according to Examples 1 to 5 to PBT, which is a polar polymer, a peel test was conducted according to JIS K 6854 as in Experimental Example 1. The results are shown in Table 4.

  Next, even when the hot melt compositions according to Comparative Examples 1 to 3 used in Experimental Example 1 were used, the adhesion test of two PBTs to each other was similarly performed. The results are shown in Table 5.

  It is clear from Tables 2 to 5 that Comparative Examples 1 and 2 showed relatively good adhesion to PBT, which is a polar polymer, but poor adhesion to nonpolar polymers. In Comparative Example 3, although the adhesion between nonpolar polymers was relatively good, the adhesion between polar polymers was remarkably inferior. Moreover, about the comparative example 4, it was inferior to the adhesiveness of nonpolar polymers. In contrast, the hot melt compositions according to Examples 1 to 5 are inferior in adhesion between polar polymers and nonpolar polymers as compared with the hot melt compositions according to Comparative Examples 1 to 4. It was good.

Experimental example 3
Next, a waterproof test was performed on the hot melt compositions according to Examples 1 to 5 and Comparative Examples 1 to 4. As shown in FIG. 3, the waterproof test is performed by immersing the waterproof connector 1 with holes 11 from the bottom surface of the connector housing 3 to the connection terminals 5 in water, sending air into the holes 11, and molding resin 6 and the connector housing 3. This was done by measuring the air pressure when an air leak occurred. The results are shown in Table 6.

  As is apparent from Table 6, it can be seen that the hot melt compositions according to Examples 1 to 5 are more waterproof than the hot melt compositions according to Comparative Examples 1 to 4.

Experimental Example 4
Next, a salt water pressure leak test (waterproof limit test) was performed on the hot melt compositions according to Examples 1 to 5 and Comparative Examples 1 to 4. As shown in FIG. 4, in the salt water pressure-resistant leak test, the press contact terminal 22 held by the connector housing 21 is attached to one end of the cable 23, and the press contact portion is molded with a mold resin 24 made of a hot melt composition. Is immersed in a sodium chloride aqueous solution 26 in a test tank 27 together with a metal electrode 25 connected to the other end of the cable 23. In this state, a DC voltage is applied between the pressure contact terminal 22 and the metal terminal 25 by a DC power source 30 via a standard resistor 29, and the voltage across the standard resistor 29 is monitored by a voltmeter 31. Measure the time until the leakage current is observed. The test was performed under a temperature cycle environment inside the thermostatic chamber 28. The results are shown in Table 7.

  As is clear from Table 7, it can be seen that the hot melt compositions according to Examples 1 to 5 are superior in waterproof limit, that is, waterproof durability, to the hot melt compositions according to Comparative Examples 1 to 4.

It is a disassembled perspective view of the waterproof connector which concerns on one Embodiment of this invention. It is A-A 'sectional drawing of FIG. It is a figure corresponding to FIG. 2 of the waterproof connector used for Experimental example 3. FIG. It is a schematic block diagram of the saltwater pressure-resistant leak test apparatus used for Experimental example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Waterproof connector, 2 ... Terminal accommodating chamber, 3 ... Connector housing, 4 ... Electric wire, 5 ... Connection terminal, 6 ... Mold resin.

Claims (7)

  A hot-melt composition mainly composed of maleic acid-modified polyolefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin and styrene ethylene propylene styrene rubber.   The maleic acid-modified polyolefin resin is 5 to 25% by weight, the C9 hydrogenated petroleum resin is 15 to 50% by weight, the amorphous polyolefin is 30 to 55% by weight, and the styrene ethylene propylene styrene rubber is 1 to 20% by weight. The hot melt composition according to claim 1.   The maleic acid-modified polyolefin resin is 10 to 20% by weight, the C9 hydrogenated petroleum resin is 35 to 40% by weight, the amorphous polyolefin is 35 to 50% by weight, and the styrene ethylene propylene styrene rubber is 5 to 15% by weight. The hot melt composition according to claim 1. A plurality of wires in which the core wire is covered with an insulating coating made of a nonpolar polymer;
A plurality of connection terminals connected to the plurality of electric wires;
A connector housing made of a polar polymer having a terminal accommodating hole for accommodating the plurality of connection terminals therein;
In a waterproof connector provided with a mold resin that prevents moisture from entering the terminal housing hole of the connector housing and seals the connection portion between the electric wire and the connection terminal inside the connector housing.
The waterproof resin characterized in that the mold resin is mainly composed of maleic acid-modified olefin resin, C9 hydrogenated petroleum resin, amorphous polyolefin and styrene ethylene propylene styrene rubber. The connection terminal has a fitting connection portion that is fitted to the counterpart connection terminal, and a wire connection portion that is formed on the proximal end side of the fitting connection portion and connected to the electric wire,
The waterproof connector according to claim 4, wherein the mold resin seals the wire connecting portion.   The mold resin is 5 to 25% by weight of the maleic acid-modified polyolefin resin, 15 to 50% by weight of the C9 hydrogenated petroleum resin, 30 to 55% by weight of the amorphous polyolefin, and 1 to 1 of styrene ethylene propylene styrene rubber. The waterproof connector according to claim 4, wherein the waterproof connector is 20% by weight. The mold resin is 10 to 20% by weight of the maleic acid-modified polyolefin resin, 35 to 40% by weight of the C9 hydrogenated petroleum resin, 35 to 50% by weight of the amorphous polyolefin, and 5 to 5% of styrene ethylene propylene styrene rubber. 6. The waterproof connector according to claim 4, wherein the waterproof connector is 15% by weight.

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