JP2011032393A - Resin composition for molding excellent in low-temperature property - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for molding maintaining adhesion to a polyolefin, a metal, and PVC, excellent in flexibility with a low hardness while being excellent in molding properties with a low viscosity, excellent in elongation at lower temperatures, and capable of being preferably used as a hot melt material. <P>SOLUTION: This resin composition for molding includes an aromatic polyester (a), a tackifier (b), a polyol compound (c) having two or more hydroxy groups in a molecule, a polyolefin (d), and a polytetramethylene ether glycol (e), in which the content of the polyolefin (d) is 5 to 40 pts.mass, relative to 100 pts.mass of the total of the aromatic polyester (a) and the polyolefin (d) and the content of the PTMG (e) is 1 to 20 pts.mass based on 100 pts.mass of the total of the aromatic polyester (a) and the polyolefin (d). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an aromatic polyester resin composition. Specifically, the present invention relates to a molding resin composition or a sealing resin composition made of an aromatic polyester resin composition, or a hot melt material or a potting material made of an aromatic polyester resin composition.

  Moisture enters an electric wire, such as a harness, used in an automobile or the like from a ground portion or the like. Usually, in order to prevent the moisture from entering the automobile, the conductor 63 that is joined to the joining portion 62 via the caulking portion 61 is cut off in the middle of the harness 60 shown in FIG. It was necessary to provide. For this reason, there is a problem that the design and the like are restricted by the wiring turning, which is disadvantageous in terms of cost.

  Further, for the connector, a method such as injection-curing a one-pack type silicone resin composition or the like to make it waterproof and water-stopping, specifically, the molded part 71 is made of ethylene / propylene as in the connector 70 shown in FIG. It is known that a one-pack type silicone resin composition or the like is injected into a portion where a joint 72 and a conductor 73 are joined using a rubber member such as a copolymer (EPDM). Since the curing time of the resin composition or the like is long, there is a problem that it is necessary to leave it for about 1 to 2 hours in the factory.

Various polyester resins having characteristics such as flexibility, heat resistance, chemical resistance, oil resistance, stretchability and moldability are known. However, conventionally known polyester resins having some of the above characteristics have a problem that the balance between moldability and flexibility is poor and cannot be used as a hot melt material for molding. For example, if the resin is low viscosity and easy to mold, the flexibility after molding is very low, and conversely, molding is difficult with a resin having flexibility.
Other examples include urethane hot melts, polyamide hot melts, EVA hot melts, and silicone fillers, but they cannot be used as molding hot melt materials.

  In response to the above problems, the present inventors have proposed a molding resin composition that contains an aromatic polyester and can be used as a molding hot melt resin composition (Patent Documents 1 and 2).

  By the way, soft polyvinyl chloride (PVC) has been conventionally used as a coating material for wires of harnesses and connectors. However, conversion to polyolefin-based materials is being promoted for dehalogenation.

  However, the molding resin compositions described in Patent Documents 1 and 2 are excellent in flexibility, heat resistance and stretchability, and further have low viscosity and excellent moldability, but the adhesion to polyolefin is not sufficient. It was.

  On the other hand, hot melts containing polyolefin as a main component could improve adhesion to polyolefins but could not secure adhesion to metals and PVC. Usually, since a metal is used for the caulking portion of the harness, the polyolefin-based hot melt cannot be used as these sealing materials.

  In order to solve the above problems, the present inventors include an aromatic polyester, a tackifier, a polyol compound, and a polyolefin, and are excellent in adhesiveness to polyolefin, metal, and PVC. The resin composition for molding which can be used as was proposed (patent document 3).

JP 2003-213099 A JP 2004-210893 A JP 2007-70444 A

  The molding resin composition described in Patent Document 3 is excellent in adhesion to polyolefins, metals and PVC and gasoline resistance. In particular, when a polyolefin having a polar group is used, it is aromatic even after being melted for a long time. Group polyester and polyolefin do not separate and maintain adhesion, but if you try to fill the case with glass fiber reinforced resin or metal with a small linear expansion coefficient on all sides, the low temperature Under heat shock such as from high to high, the adhesive interface could not withstand the expansion and contraction of the molding resin composition, resulting in peeling or cracking, which sometimes deteriorated waterproof performance and moisture proof performance. In particular, since the molding resin composition did not have sufficient elongation at low temperatures, peeling and cracking were likely to occur.

  Therefore, the present invention is a hot melt material that maintains adhesiveness to polyolefins, metals and PVC, has low viscosity and excellent moldability, yet has low hardness and flexibility, and is excellent in elongation at low temperatures. An object of the present invention is to provide a molding resin composition that can be suitably used.

  As a result of intensive studies, the present inventor contains aromatic polyester, tackifier, polyol compound, polyolefin, and polytetramethylene ether glycol (hereinafter referred to as “PTMG”; the structure is represented by the following chemical formula). The inventors have found that when the PTMG content is in a specific range, they have excellent adhesion to polyolefins, metals and PVC and low temperature properties, thereby completing the present invention.

That is, the present invention is as follows.
[1] Aromatic polyester (a), tackifier (b), polyol compound (c) having two or more hydroxy groups in one molecule, polyolefin (d) having polar groups, and polytetramethylene ether Glycol (e), the content of the polyolefin (d) is 5 to 40 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d), and The molding resin composition in which the content of the polytetramethylene ether glycol (e) is 1 to 20 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d).
[2] The molding resin composition according to [1], wherein the polar group is at least one selected from the group consisting of an epoxy group, a carboxy group, and an acid anhydride group.
[3] The molding resin composition according to [1], wherein the polyolefin (d) has an epoxy group, a carboxy group, and / or an acid anhydride group.
[4] The molding resin composition according to the above [2] or [3], wherein the carboxy group is a carboxy group derived from maleic acid, and the acid anhydride group is a maleic anhydride group.
[5] The above [1] to [4], wherein the content of the tackifier (b) is 1 to 50 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d). ] The molding resin composition in any one of.
[6] The above [1], wherein the content of the polyol compound (c) is 0.5 to 50 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d). [5] The molding resin composition according to any one of [5].
[7] The molding resin composition according to any one of [1] to [6], wherein the viscosity at 190 ° C. is 10 to 500 Pa · s.

[8] The aromatic polyester (a) is selected from the group consisting of an acid component containing terephthalic acid and / or isophthalic acid, ethylene glycol, neopentyl glycol, 1,4-butanediol, and polytetramethylene ether glycol. The molding resin composition according to any one of the above [1] to [7], which is a polyester obtained by reacting a hydroxy group component containing at least one selected.
[9] The aromatic polyester (a) is
Polyester A obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing 1,4-butanediol and polytetramethylene ether glycol;
Polyester D obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing ethylene glycol and neopentyl glycol;
The molding resin composition according to any one of the above [1] to [8], which contains
[10] The aromatic polyester (a) is obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing ethylene glycol, neopentyl glycol and 1,4-butanediol. The molding resin composition according to the above [9], further comprising polyester B.
[11] The aromatic polyester (a) is obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing ethylene glycol, neopentyl glycol and 1,4-butanediol. The molding resin composition according to [9] or [10], further including polyester C obtained.
[12] The molding resin composition according to any one of [1] to [11], wherein the tackifier (b) is a rosin tackifier.
[13] The molding resin composition according to [12], wherein the rosin tackifier is rosin diol.

  The molding resin composition of the present invention is excellent in adhesion to polyolefin, metal and PVC and low temperature properties. In particular, when a polyolefin having a polar group is used, the aromatic polyester and the polyolefin are not separated even after the molding resin composition of the present invention is melted for a long time, and the adhesiveness can be maintained.

(A) of FIG. 1 is a figure which shows the conducting wire before shaping | molding, (B) is a figure which shows the shape (mold single side | surface) of a mold, (C) is a figure which shows the shape of the mold at the time of shaping | molding (D) is a figure which shows the shape of a molded article. FIG. 2 is a view showing a harness sealed with the molding resin composition of the present invention. 3A and 3B are a perspective view and a cross-sectional view, respectively, showing an adhesion test sample with polyvinyl chloride (PVC). 4A and 4B are a perspective view and a cross-sectional view, respectively, showing an adhesion test sample with a metal (tin-plated copper plate). 5A and 5B are a perspective view and a cross-sectional view, respectively, showing an adhesion test sample with polypropylene (PP). FIG. 6 is a view showing a connector of the current product. FIG. 7 is a diagram showing a connector of the current product.

Hereinafter, the present invention will be described in more detail.
The molding resin composition of the present invention (hereinafter also referred to as “the composition of the present invention”) has an aromatic polyester (a), a tackifier (b), and two or more hydroxy groups in one molecule. A polyol compound (c), a polyolefin (d), and PTMG (e) are contained, and the content of the polyolefin (d) is 100 masses in total of the aromatic polyester (a) and the polyolefin (d). 5 to 40 parts by mass with respect to parts, and the PTMG (e) content is 1 to 20 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d). Part of the molding resin composition.

<Aromatic polyester (a)>
The aromatic polyester (a) is not particularly limited, and a known aromatic polyester can be used without particular limitation, but is preferably an aromatic polyester obtained from a condensation reaction of a fatty acid and a glycol.
Specific examples of the aromatic polyester (a) include an acid component containing one or more selected from the group consisting of terephthalic acid, isophthalic acid, sebacic acid and ε-caprolactone, and ethylene glycol (hereinafter “ EG ”), neopentyl glycol (hereinafter sometimes referred to as“ NPG ”), polytetramethylene ether glycol (hereinafter sometimes referred to as“ PTMG ”), and 1,4. -Aromatic polyester containing polyester obtained by reacting with a hydroxyl group component containing at least one selected from the group consisting of butanediol (hereinafter sometimes referred to as “1,4-BD”) Is mentioned.
Preferably, aromatic polyesters containing at least one polyester selected from the group consisting of polyesters A, B, C and D described below can be exemplified.
More preferably, an aromatic polyester containing (in combination) two or more kinds of polyesters selected from the group consisting of polyesters A, B, C and D can be exemplified.

<Polyester A>
Polyester A is a polyester obtained by a condensation reaction of an acid component composed of a mixture of terephthalic acid and isophthalic acid and a hydroxy group component composed of a mixture of 1,4-BD and PTMG.

The melt index (melt index) (hereinafter abbreviated as “MI”), which is a measure of the fluidity of the polyester A in the molten state, is preferably 10 or more at 200 ° C., more preferably 13-50. preferable.
When the MI of polyester A is within this range, the viscosity at the time of molding is kept low, and the heat resistance after molding is excellent.

PTMG as the hydroxy group component of polyester A can be used without particular limitation as long as it is a polymer obtained by ring-opening polymerization of tetrahydrofuran or a polymer having the same structure as that polymer.
The number average molecular weight (Mn) of the PTMG is not particularly limited, but is preferably about 2000 or more. As a commercial product of PTMG, for example, H-283 (manufactured by Mitsubishi Chemical Corporation, Mn = 2000) can be used.
Specifically, for example, Hytrel 4057 (manufactured by Toray DuPont) can be used as the polyester A.

<Polyester B>
Polyester B is a polyester obtained by a condensation reaction between an acid component composed of a mixture of terephthalic acid, isophthalic acid and ε-caprolactone and a hydroxy group component composed of a mixture of 1,4-BD and PTMG.
The viscosity of Polyester B at 190 ° C. is preferably 100 to 300 Pa · s, and more preferably 150 to 200 Pa · s.
Specifically, for example, Elitel UE3800 (manufactured by Unitika) can be used as the polyester B.

<Polyester C>
Polyester C is a polyester obtained by a condensation reaction of an acid component composed of a mixture of terephthalic acid and isophthalic acid and a hydroxy group component composed of a mixture of EG, NPG, and 1,4-BD.
The viscosity of Polyester C at 190 ° C. is preferably 0.5 to 2 Pa · s, and more preferably 0.7 to 1.5 Pa · s.
Specifically, for example, Elitel UE3510 (manufactured by Unitika) can be used as the polyester C.

<Polyester D>
Polyester D is a polyester obtained by a condensation reaction of an acid component composed of a mixture of terephthalic acid and isophthalic acid and a hydroxy group component composed of a mixture of EG and NPG.
The viscosity of Polyester D at 190 ° C. is preferably 0.5 to 2 Pa · s, and more preferably 0.7 to 1.5 Pa · s.
Specifically, for example, Elitel UE3320 (manufactured by Unitika) can be used as the polyester D.

  In the present invention, the aromatic polyester (a) is preferably used in combination with at least two selected from the group consisting of the polyesters A, B, C and D. The polyester A and the polyester D It is more preferable to use together. This is for molding of the present invention obtained by using together polyester A excellent in flexibility, heat resistance, chemical resistance, oil resistance and stretchability and polyester D having low viscosity and excellent moldability. This is because the viscosity at the time of molding of the resin composition is kept low, and further, a high flexibility is given to the solidified product after molding. For the same reason, the aromatic polyester (a) preferably uses the polyester A and polyester D and the polyester C and / or polyester B in combination.

  In the present invention, the content ratio of the polyesters A, B, C and D in the aromatic polyester (a) is not particularly limited, but the polyester A is added to the total mass of the aromatic polyester (a). 10 to 50% by mass, 0 to 30% by mass of the polyester B, 0 to 30% by mass of the polyester C, 10 to 50% by mass of the polyester D, and 20 to 40% of the polyester A are preferable. More preferably, the polyester B contains 0 to 25% by mass, the polyester C 0 to 20% by mass, the polyester D 25 to 45% by mass, and the polyester A 25 to 35% by mass. The polyester B is 0 to 20% by mass, the polyester C is 0 to 15% by mass, and the polyester D is 30 to 40% by mass. It is further preferred to have.

  When the content ratio of the polyesters A, B, C and D is within this range, it is possible to give flexibility to the solidified product after molding while keeping the viscosity at the time of molding of the resulting resin composition for molding. The solidified product after molding is preferable because it is excellent in oil resistance and gasoline resistance. Furthermore, it is preferable because the curing time after molding is short and there is no need for curing.

  Further, the composition of the present invention having such properties is excellent in heat shock resistance and can follow the expansion and contraction of the adherend during the heat cycle, and therefore can be used as a hot melt material for molding. preferable.

<Tackfire (b)>
As the tackifier (b), a conventionally known tackifier (tackifier) can be used, and specific examples include rosin tackifiers, terpene tackifiers, and petroleum resin tackifiers.

  Examples of the rosin tackifier include esters of rosin acid and glycerin and pentaerythritol, which are mainly composed of abietic acid in pine jani and pine root oil, and hydrogenated products and disproportionates thereof. Preferable examples include gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin, rosin ester (rosin diol) and the like.

  Examples of the terpene tackifier include those obtained by polymerizing natural terpenes contained in terpene oil and orange peel contained in pine, specifically, terpene resins, aromatic modified terpene resins, terpene phenol resins, Preferred examples include hydrogenated terpene resins.

  Examples of the petroleum resin tackifier include aliphatic, alicyclic, and aromatic resins made from petroleum. Specifically, C5 petroleum resins, C9 petroleum resins, copolymer petroleum resins, Suitable examples include alicyclic saturated hydrocarbon resins and styrene petroleum resins.

  Among these, as the tackifier (b), it is preferable to use the rosin-based tackifier because the resulting composition has a low viscosity and is easy to mold. Specifically, rosin diol, which is a rosin ester, is used. The moldable resin composition to be used is more preferable because the stretchability, adhesion to polyolefin, metal and PVC are improved, and the balance between heat resistance and flexibility and gasoline resistance are improved. Specific examples of rosin diol include Pine Crystal D-6011, KE-615-3, and D-6240 (all manufactured by Arakawa Chemical Industries).

  Moreover, 1-50 mass parts is preferable with respect to the total 100 mass parts of the said aromatic polyester (a) and the said polyolefin (d), and, as for content of the said tackifier (b), 10-40 mass parts is more. preferable. Within this range, the stretchability of the moldable resin composition obtained, the adhesion to polyolefin, metal and PVC are improved, and the balance between heat resistance and flexibility and gasoline resistance are improved.

<Polyol compound (c)>
The polyol compound (c) is a polyol compound having two or more hydroxy groups in one molecule, and functions as a compatibilizing agent for compatibilizing the aromatic polyester (a) and the tackifier (b). Is not particularly limited, and specific examples include ethylene glycol, propylene glycol, butanediol, polycarbonate diol, polycaprolactone, diethylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol, and the like. Polyether glycol such as polyethylene glycol, polypropylene glycol, polyoxypropylene diol, polyoxypropylene triol, polyoxypropylene glycol; polybutane diene polyol, polyisopreng Polyolefin polyols call like; adipate polyol; polyhydric alcohols such polyester polyols such as castor oil; lactone polyol resorcinol, polyhydric phenols such as piston phenol can be used. Each of these polyols may be used alone or in combination of two or more.

  Among these, it is preferable to use polycarbonate diol and polycaprolactone because the effect as a compatibilizer can be obtained in a small amount, and it is more preferable to use polycarbonate diol because of its high temperature and high humidity resistance.

  Moreover, 500-10000 are preferable, as for the average molecular weight of each polyol, 1000-10000 are more preferable, and 2000-10000 are still more preferable.

  The content of the polyol compound (c) is preferably 0.5 to 50 parts by mass and more preferably 1 to 20 parts by mass with respect to a total of 100 parts by mass of the aromatic polyester (a) and the polyolefin (d). 2 to 10 parts by mass is preferable. Within this range, the aromatic polyester (a) and the tackifier (b) are sufficiently compatible, and the physical properties (heat resistance, flexibility, gasoline resistance) of the polyester are not lowered.

  Since the composition of the present invention contains the tackifier (b) and the polyol compound (c), as described above, the stretchability and the adhesion to polyolefin, metal and PVC are improved, and the heat resistance and flexibility are improved. In addition, the separation of the aromatic polyester (a) and the tackifier (b) that occurs at the time of melting is prevented, and the oil resistance, particularly gasoline resistance, is reduced when the tackifier (b) is added alone. It becomes. This is considered to be because the tackifier (b) is preferentially taken into the amorphous part of the aromatic polyester (a) by adding the polyol compound (c).

<Polyolefin (d)>
The polyolefin (d) is not particularly limited, but specifically, for example, homopolymers of α-olefins such as ethylene, propylene, butylene, pentene, 4-methyl-1-pentene, and the like of these α-olefins. Examples thereof include a copolymer composed of two or more kinds, or a polyolefin resin composed of a copolymer of these α-olefin and another copolymerizable monomer. These may be used alone or in combination of two or more. Among these polyolefins, polyethylene is preferable because it is more excellent in gasoline resistance.

The polyolefin (d) has a polar group.
In general, polyolefin has a low polarity, whereas the aromatic polyester (a) has a high polarity, so that the composition of the present invention is melted for a long time during or after the production of the composition of the present invention. In this case, the aromatic polyester (a) and the polyolefin (d) are separated, and even if they are stirred again, they cannot be sufficiently mixed and the adhesiveness may be lowered. On the other hand, when the said polyolefin (d) has a polar group, it does not isolate | separate even after long-time melting | fusing and can maintain adhesiveness.
The polar group is not particularly limited, and specific examples include an epoxy group, a carboxy group, an acid anhydride group, an amino group, an isocyanate group, a hydroxy group, a nitro group, and a sulfone group. The polyolefin (d) may have only one of these functional groups or may have a plurality of types of functional groups.
The polar group is preferably at least one selected from the group consisting of an epoxy group, a carboxy group, and an acid anhydride group, and more preferably an epoxy group, from the viewpoint of excellent adhesion to polar substances.
The polyolefin (d) preferably has an epoxy group and a carboxy group and / w or an acid anhydride group.
The carboxy group is preferably a carboxy group derived from maleic acid, and the acid anhydride group is preferably a maleic anhydride group.

  The polyolefin having the polar group can be obtained, for example, by a method of copolymerizing an olefin and a polymerizable monomer having a polar group (for example, glycidyl methacrylate). Moreover, you may use a commercial item.

  Content of the said polyolefin (d) is 5-40 mass parts with respect to a total of 100 mass parts of the said aromatic polyester (a) and the said polyolefin (d). Since the composition of this invention contains polyolefin (d) in this range, it is excellent in the balance of the adhesiveness with respect to polyolefin, and the adhesiveness with respect to a metal and PVC, and is excellent also in gasoline resistance. From the point which is excellent by these characteristics, as for content of the said polyolefin (d), 10-40 mass parts is more preferable with respect to a total of 100 mass parts of the said aromatic polyester (a) and the said polyolefin (d), 20-20. More preferred is 40 parts by weight.

  Since the composition of the present invention contains the polyolefin (d) in a specific ratio, it can improve the adhesion to polyolefin while maintaining excellent properties such as adhesion to metals and PVC and gasoline resistance. it can. In particular, when the polyolefin having the polar group is used, the adhesiveness can be maintained without separation even after melting for a long time.

<PTMG (e)>
The PTMG (e) is not particularly limited as long as it is a polymer obtained by ring-opening polymerization of tetrahydroxyfuran in the presence of an acid catalyst or a compound (polytetramethylene ether glycol) having the same structure as this polymer. The PTMG contained in the aromatic polyester (a) as a monomer component may be the same compound or different compounds.

  The number average molecular weight (Mn) of PTMG contained in the composition of the present invention is not particularly limited, but is preferably about 500 to 3000, more preferably about 500 to 2500, still more preferably about 1000 to 2500, and about 1000 to 2000. Is more preferable. A preferred PTMG structure is represented by the following chemical formula (1).

  The amount of PTMG contained in the composition of the present invention is particularly limited as long as it is within the range of 1 to 20 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d). However, 1-15 mass parts is preferable, 1-10 mass parts is more preferable, 2-8 mass parts is further more preferable, and 3-7 mass parts is still more preferable. Within this range, the flexibility and elongation at low temperatures of the composition of the present invention are improved.

  Examples of commercially available products of PTMG include PTMG650, PTMG1000, PTMG2000, PTMG3000 (above, manufactured by Mitsubishi Chemical Corporation, Mn = 650,1000,2000,3000), PolyTHF (BASF, Mn = 650, 1000, 2000), TERATHANE (INVISTA, Mn = 250, 650, 1000, 1400, 1800, 2000, 2900) can be used.

  The composition of the present invention includes other lubricants such as a reinforcing agent, an anti-aging agent, an antioxidant, a filler, a plasticizer, a heat stabilizer, and an ultraviolet absorber as long as the object of the present invention is not impaired. Various additives such as waxes, colorants, crystallization accelerators and reinforcing fibers may be blended.

  The production method of the composition of the present invention is not particularly limited, and the aromatic polyester (a), the tackifier (b), the polyol compound (c), the polyolefin (d), the PTMG (e), and necessary Depending on the conditions, various additives can be mixed and produced by, for example, a roll, a kneader, an extruder, a universal stirrer or the like.

The composition of the present invention described above preferably has a viscosity at 190 ° C. of 10 to 500 Pa · s, more preferably 10 to 100 Pa · s, from the viewpoint of excellent moldability.
Moreover, it is preferable that it is a molding resin composition which can be discharge-molded on the conditions that a pressure is less than 5 MPa, Preferably it is 0.2-1.0 MPa, More preferably, it is 0.3-0.5 MPa.
Here, the discharge molding is preferably performed in the range of 120 to 230 ° C, and more preferably in the range of 180 to 210 ° C. If it is this temperature range, stability of the molding resin composition used for the said discharge molding will improve, and also the viscosity at the time of a melt | fusing will be within the range mentioned above.
Moreover, a pressure is a pressure at the time of discharging the said resin composition for a molding from a discharge outlet at the time of the said discharge molding.

  The composition of the present invention described above is excellent in adhesion to polyolefin, metal and PVC, gasoline resistance, stretchability and flexibility. In addition, it has low viscosity and excellent moldability. In particular, when a polyolefin having a polar group is used, the aromatic polyester and the polyolefin are not separated even after the molding resin composition of the present invention is melted for a long time, and the adhesiveness can be maintained.

  Since the composition of the present invention has the above-described excellent characteristics, it is useful as a sealant / waterproof protectant for ends of connectors / harnesses, etc. In order to protect against impact, vibration, moisture, etc., it is also useful as a filler embedded in the entire electric circuit.

  A method for producing a waterproof protective coating using the composition of the present invention is a method for producing a waterproof protective coating in which a waterproof protective coating is formed on the end of an electronic device using the molding resin composition of the present invention described above. A melting step for melting the molding resin composition of the present invention, and a discharge molding / application step for discharging or applying the molten molding resin composition after the melting step to the electronic device at a pressure of less than 5 MPa; It is a manufacturing method of the waterproof protective coating characterized by comprising. Here, the pressure at the time of discharge molding or application is preferably 0.2 to 1.0 MPa, and more preferably 0.3 to 0.5 MPa.

  The melting step is a step of melting the composition of the present invention, and specifically, a step of heating the moldable resin composition to 160 to 230 ° C., preferably 180 to 210 ° C. to melt.

The discharge molding / coating step is a step of discharging or applying the molding resin composition melted in the melting step to the end portion of the electronic device with a pressure of less than 5 MPa. Specifically, the above-mentioned discharge molding is performed by using a hot melt gun, a hot melt applicator, and a molten resin composition for molding in a mold containing an electronic device end at a pressure of less than 5 MPa, preferably 1 to 4 MPa. It is the process of discharging using etc. and shape | molding in the said mold. Or it is the process of discharging by a hot melt gun and a hot melt applicator, and potting.
The application is a step of applying the molten molding resin composition to the end portion of the electronic device using a hot melt gun spray or the like at a pressure of less than 5 MPa, preferably 1 to 4 MPa. In general injection molding, the pressure is as high as 40 to 120 MPa and the melting temperature is as high as 250 to 300 ° C., whereas if the method for producing a waterproof protective coating using the composition of the present invention is used, the pressure is 0.3 to Since it can be used at 0.5 MPa and a melting temperature of 180 to 230 ° C., it is very excellent.

Therefore, if the manufacturing method described above is used, molding at such a low temperature and low pressure is possible. Therefore, as shown in FIGS. 1A to 1D, the polyolefin-coated conductor 2 having the peeling portion 1 is used. This is preferable because a manufacturing apparatus using the aluminum mold 3 and the rubber packing 4 can be used, and the cost for molding can be reduced.
Specifically, in the shape of the mold shown in (C) (sealed with the aluminum mold 3 and the rubber packing 4), hot melt (HM) material is injected from the injection portion 5 (arrow direction), The HM material is passed through the injection path 6 and transferred to the HM molding mold 7. Thereafter, the HM material is molded with the HM molding mold 7 and removed from the mold, thereby forming a molded product having a molding portion 8 indicated by (D).
In addition, since it can be molded at low temperatures and low pressures, it can be molded without damaging electronic components on the substrate, so that the entire substrate can be waterproofed, and a one-part silicone resin composition, etc. In addition, since it is not necessary to cover the substrate and the electronic component with a case, the cost of the product can be reduced, which is preferable.

In addition, molding of two-component urethane and epoxy requires heating and the like, and further curing takes about 15 to 120 minutes. On the other hand, when the composition of the present invention is used, the curing time after molding is naturally cooled. The process is preferably completed in several seconds to several tens of seconds, and can be removed from the mold within several minutes.
Specifically, the use of the composition of the present invention is preferable because the injection time of the HM material for molding is completed in 10 seconds and the mold can be released from the mold within 1 minute by natural cooling.
Furthermore, since there is no deformation after demolding and no curing is required, the productivity is also excellent.

Specific examples of the end of the electronic device include, for example, an end of a connector / harness, a connection portion of a cord and a cord, a substrate of an electronic device, etc., and the material thereof is metal, PVC, polyolefin or the like. There are many things.
Therefore, the waterproof protective coating formed on the end portion of the electronic device is excellent in adhesion to metal, PVC and polyolefin, such as the end portion of the connector / harness, the connection portion between the cord and the cord, the electronic This is preferable because it can be used for a substrate of an apparatus.
In particular, in a harness used in an automobile in which moisture enters from a ground portion or the like, a waterproof protective coating manufactured by the above-described method is used for the molded portion 21 as shown in the harness 20 of FIG. For example, there is no need to cut the conducting wire 23 joined to the joining portion 22 through the molding portion 21 in the middle or to provide an atmosphere opening portion, so that the design is not restricted and the cost is low. It is preferable because of its excellent mass productivity.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
(Polyester A, C, D)
The polyester only needs to contain the desired acid component and glycol component. As polyester A, Hytrel 4057 manufactured by Toray DuPont, Unitika Elitel UE3510 as polyester C, and Unitika Elitel UE3320 as polyester D are used. used. The molar ratio of the acid component and the hydroxy group component of polyesters A, C and D is shown in Table 1 below.

(Examples 1-6 and Comparative Examples 1-4)
The components shown in Table 2 below were mixed using a kneader at the composition (parts by mass) shown in Table 2 to obtain each molding resin composition shown in Table 2.
Each measurement shown below was performed in each obtained resin composition for molding.

<Viscosity>
The viscosity was measured according to JIS K 7117-1: 1999.
Using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.), the obtained molding resin composition was melted at 190 ° C. for 30 minutes, and then rotated using a No. 3 rotor, and the viscosity was measured at 10 rpm. Those having a viscosity within the range of 1 to 500,000 mPa · s were evaluated as “◯”, and those not within this range were evaluated as “×”, and the evaluation results are shown in Table 2.

<Separation>
About the thing which cooled and solidified the resin composition for shaping | molding which aged by allowing the produced resin composition for molding to stand at 200 degreeC for 24 hours or 72 hours, the mixing state of each composition component was confirmed visually. Those that were in a compatible state were evaluated as “◯”, those that were in a separated state were evaluated as “×”, and those that were gelled were evaluated as “#”, and the evaluation results are shown in Table 2.
In Comparative Example 4, since gelation occurred, tests for low temperature property, adhesiveness, and moldability were not performed (indicated as “NA” in Table 2).

<Bleedability>
The obtained molding resin composition was allowed to stand in a constant temperature room at 20 ° C. for 30 days, and bleed out to the surface of the composition was visually confirmed. The case where no bleed occurred was evaluated as “◯”, the case where bleed occurred was evaluated as “x”, and the evaluation results are shown in Table 2.

<Flexibility>
The obtained molding resin composition was cooled and solidified, pressed to a thickness of 1 mm with a 140 ° C. press, cut into a 25 mm × 100 mm × 1 mm sheet, and used as a test piece.
The test piece was folded in half. The test piece that was not broken was evaluated as “◯”, and the broken piece was evaluated as “×”. The evaluation results are shown in Table 2.

<Adhesiveness>
(1) Adhesiveness to PVC Adhesiveness to PVC was measured according to JIS K 6256: 1999. 3 mm thick PVC (trade name: Tough Neil, Takafuji Co., Ltd.) was cut into 25 mm × 150 mm and used as a PVC test piece 30. The obtained molding resin composition 31 is molded on a PVC test piece 30 as shown in FIG. 3 (A) using a mold to create a PVC adhesion test sample, as shown in FIG. 3 (B). The PVC test piece 30 and the molding resin composition 31 are subjected to a 180-degree peeling test in which tensile stress is applied in the directions of the two arrows so that the PVC test piece 30 and the molding resin composition 31 are separated. The tensile stress (maximum tensile stress) when starting to peel off the object 31 was measured. The pulling speed was 50 mm / min.
The PVC adhesiveness of the molding resin compositions of the examples and comparative examples was evaluated as “◎” as the PPC adhesiveness being particularly excellent when the maximum tensile stress was 150 N / 25 mm or more, and 50 N / 25 mm or more and 150 N. Those having a thickness of less than / 25 mm were evaluated as “◯” because the PPC adhesiveness was excellent, and those having a thickness of less than 50 N / 25 mm were evaluated as “X” because the PPC adhesiveness was inferior. The measured values and evaluation results of the maximum tensile stress are shown in Table 2.

(2) Adhesiveness to metal As shown in FIG. 4A, metallic adhesiveness is obtained by bonding two tin-plated copper plates 40 having a width of 25 mm, a length of 100 mm, and a thickness of 0.8 mm with a molding resin composition 41. Then, a metal adhesion test sample with a lapping margin of 10 mm was prepared, and as shown in FIG. 4B, the tin-plated copper plate 40 was pulled from both directions at a pulling speed of 50 mm / min, and the shear strength was measured.
As for the metal adhesiveness of the molding resin composition, those having a shear strength of 2.0 N / mm ² or more are evaluated as “◯” as being excellent in metal adhesion, and those having a shear strength of less than 2.0 N / mm ² are metal. It evaluated as "x" as inferior to adhesiveness. The measured values and evaluation results are shown in Table 2.

(3) Adhesiveness to polypropylene (PP) A PP test piece 50 was prepared in the same manner as the above PVC test piece, except that a corona surface-treated polypropylene (manufactured by Shin-Kobe Electric Machinery Co., Ltd .: PP-N-BN) was used. A molding resin composition 51 was molded on a PP test piece 50 as shown in FIG. 5A using a mold to prepare a PP adhesion test sample, which was used as a PP adhesion test sample. As shown in FIG. 5 (B), this test sample was subjected to a 90 ° peeling test in accordance with JIS K 6256: 1999, and the PP test piece 50 and the molding resin composition 51 were obtained at a tensile speed of 50 mm / min. The tensile stress (maximum tensile stress) when starting to peel was measured, and this was taken as the measured value.
With respect to the molding resin compositions of Examples and Comparative Examples, the measured values of PP adhesiveness are shown in the PP adhesiveness column of Table 2. When the measured value is “ND”, the PP test piece 50 and the molding resin composition 51 peeled off when the test piece was attached to the testing machine, and the maximum tensile stress could not be measured. . The evaluation of PP adhesiveness was evaluated as “◯” when the maximum tensile stress was 50 N / 25 mm or more, and “X” when the maximum tensile stress was less than 50 N / 25 mm. Moreover, when the test piece was attached to the testing machine, the PP test piece 50 and the molding resin composition 51 were peeled off, and the measured value was “ND”, and “×” was also evaluated.

<Moldability>
The PVC coated cord was molded using an aluminum mold and rubber packing manufacturing apparatus shown in FIG.
(1) Mold injection property Using a hot melt applicator, the molding resin composition thus obtained was injected at an air pressure of 0.4 MPa, and the injection time until it was molded into a prescribed shape was measured. A sample having an injection time of 10 seconds or less was marked with “◯”.
(2) Demoldability Using the above mold, after the obtained molding resin composition was injected, the time until demolding from the mold was measured so as not to deform the shape was measured. Those that could be removed from the mold within 1 minute after injection were indicated as “◯”.

<Low temperature>
The low temperature property was measured by a method based on a tensile test (JIS K 7113: 1995). The resin composition was cooled to −40 ° C. to conduct a breaking test, the elongation of the test product up to the breaking point was measured, and the tensile breaking elongation (%) was calculated. A tensile elongation at break of 150% or higher was evaluated as “◯”, and a tensile elongation at break of less than 150% was evaluated as “X”.

Each component shown in Table 2 is as follows.
(Component a)
・ Polyester A: Hytrel 4057 (manufactured by Toray DuPont)
-Polyester C: Elitel UE3510 (manufactured by Unitika)
-Polyester D: Elitel UE3320 (manufactured by Unitika)
(Component b)
・ Rosin tackifier: Pine Crystal KE-6011 (Arakawa Chemical Industries)
(Component c)
Polycarbonate diol: Plaxel CD220 (manufactured by Daicel Chemical Industries)
(D component)
PE + GMA: Bond First 7L (manufactured by Sumitomo Chemical Co., Ltd., polyethylene having an epoxy group)
PE + GMA + MA: ADMER SF-715 (manufactured by Mitsui Chemicals, polyethylene having an epoxy group and a maleic acid group)
(E component)
-PTMG1000: PTMG1000 (Mitsubishi Chemical Corporation, Mn = 1000)
PTMG2000: PTMG2000 (Mitsubishi Chemical Corporation, Mn = 2000)
-PTMG3000: PTMG3000 (Mitsubishi Chemical Corporation, Mn = 3000)
(Other ingredients)
Plasticizer 1: Tetrax (Grade 4T, manufactured by Nippon Oil Corporation, polyisobutylene Plasticizer 2: LIR-30 (Kuraray, liquid polyisoprene rubber)
Anti-aging agent: Irganox 1010 (Ciba Specialty Chemicals, hindered phenol antioxidant)

<Comprehensive evaluation>
As is apparent from the results shown in Table 2, the composition of Comparative Example 1 is poor in flexibility and low temperature property, and the compositions of Comparative Examples 2 and 3 are separated after aging, bleeding property, flexibility, low temperature property and The adhesiveness was poor, and the composition of Comparative Example 4 gelled after aging for 72 hours, as well as poor bleeding and adhesiveness.
Therefore, about Comparative Examples 1-4, comprehensive evaluation was set to "x".

On the other hand, the molding resin compositions (Examples 1 to 6) of the present invention have a relatively low viscosity, high flexibility, and excellent PVC adhesiveness, metal adhesiveness, PP adhesiveness, moldability, and low-temperature properties. It was.
Therefore, about Examples 1-6, comprehensive evaluation was set to "(circle)".

DESCRIPTION OF SYMBOLS 1 Peeling part 2 Polyolefin covering conducting wire 3 Aluminum mold 4 Rubber packing 5 Injection | pouring part 6 Injection | pouring path | route 7 HM casting mold 8 Molding part 20 Harness 21 Molding part 22 Joining part 23 Conductor 30 PVC test piece 31 Molding resin composition 40 Tin-plated copper plate 41 Resin composition for molding 50 PP test piece 51 Resin composition for molding 60 Harness 61 Caulking part 62 Joining part 63 Conductor 64 Atmospheric release part 70 Connector 71 Molding part 72 Joining part 73 Conductor

Claims (13)

  Aromatic polyester (a), tackifier (b), polyol compound (c) having two or more hydroxy groups in one molecule, polyolefin (d) having a polar group, polytetramethylene ether glycol (e And the content of the polyolefin (d) is 5 to 40 parts by mass with respect to a total of 100 parts by mass of the aromatic polyester (a) and the polyolefin (d), and the poly The molding resin composition whose content of tetramethylene ether glycol (e) is 1 to 20 parts by mass with respect to 100 parts by mass in total of the aromatic polyester (a) and the polyolefin (d).   The molding resin composition according to claim 1, wherein the polar group is at least one selected from the group consisting of an epoxy group, a carboxy group, and an acid anhydride group.   The molding resin composition according to claim 1, wherein the polyolefin (d) has an epoxy group and a carboxy group and / or an acid anhydride group.   The molding resin composition according to claim 2 or 3, wherein the carboxy group is a carboxy group derived from maleic acid, and the acid anhydride group is a maleic anhydride group.   The content of the tackifier (b) is 1 to 50 parts by mass with respect to a total of 100 parts by mass of the aromatic polyester (a) and the polyolefin (d). Molding resin composition.   The content of the polyol compound (c) is 0.5 to 50 parts by mass with respect to a total of 100 parts by mass of the aromatic polyester (a) and the polyolefin (d). The resin composition for molding as described in 2.   The molding resin composition according to any one of claims 1 to 6, which has a viscosity at 190 ° C of 10 to 500 Pa · s.   The aromatic polyester (a) is at least selected from the group consisting of an acid component containing terephthalic acid and / or isophthalic acid, and ethylene glycol, neopentyl glycol, 1,4-butanediol, and polytetramethylene ether glycol. The molding resin composition according to any one of claims 1 to 7, which is a polyester obtained by reacting a hydroxy group component containing one kind. The aromatic polyester (a) is
Polyester A obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing 1,4-butanediol and polytetramethylene ether glycol;
Polyester D obtained by reacting an acid component containing terephthalic acid and isophthalic acid with a hydroxy group component containing ethylene glycol and neopentyl glycol;
The molding resin composition in any one of Claims 1-7 containing this.   Polyester B obtained by reacting the aromatic polyester (a) with an acid component containing terephthalic acid and isophthalic acid and a hydroxy group component containing ethylene glycol, neopentyl glycol and 1,4-butanediol The resin composition for molding according to claim 9, further comprising:   Polyester C obtained by reacting the aromatic polyester (a) with an acid component containing terephthalic acid and isophthalic acid and a hydroxy group component containing ethylene glycol, neopentyl glycol and 1,4-butanediol The resin composition for molding according to claim 9 or 10, further comprising:   The resin composition for molding according to any one of claims 1 to 11, wherein the tackifier (b) is a rosin tackifier.   The molding resin composition according to claim 12, wherein the rosin tackifier is rosin diol.

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