JP2013241496A - Method for pelletizing polyester-based molding resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for pelletizing a polyester-based molding resin composition having adhesiveness in good workability on pelletizing and without causing blocking after pelletized, and to provide polyester-based molding resin composition pellets produced by the method.SOLUTION: A method for pelletizing a polyester-based molding resin composition comprising an aromatic polyester (a), a tackifier (b), a polyol compound (c) having two or more hydroxy groups in one molecule, and a polar group-having polyolefin (d) comprises (1) a process of extruding the strand of the polyester-based molding resin composition, (2) a process of cooling the strand, (3) a process of adhering fine polyolefin-based resin particles having a dropping point of ≥100°C and an average particle size of ≤80 μm on the surface of the strand, and (4) a process of cut-pelletizing the strand; and the polyester-based molding resin composition pellet obtained by the pelletizing method.

Description

  The present invention relates to a method for pelletizing a polyester-based molding resin composition having adhesiveness.

  In an electric wire used for an automobile or the like, for example, a harness or the like, moisture enters from the ground portion. Usually, in order to prevent the moisture from entering the automobile, the conductor 53 that is joined to the joining portion 52 via the caulking portion 51 is cut off in the middle of the harness 50 shown in FIG. It was necessary to provide. For this reason, there is a problem that the design or the like is not regulated by a wiring turn or the like, which is disadvantageous in terms of cost.

  As for the connector, a method such as injection-curing a one-pack type silicone resin composition or the like, water-proofing, water-stopping, or the like. Specifically, as shown in the connector 60 shown in FIG. It is known that a one-pack type silicone resin composition or the like is injected into a portion where the joint 62 and the conductive wire 63 are joined using a rubber member such as a propylene copolymer (EPDM). Since the curing time of the silicone 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.

  On the other hand, a good balance between moldability and flexibility, that is, a resin that is low viscosity and easy to mold, yet has high flexibility after molding, or a resin that is flexible and easy to mold with low viscosity Thus, a polyester-based molding resin composition having adhesiveness that can be used as a hot-melt molding material has been proposed (Patent Documents 1 and 2).

  The polyester-based molding resin composition having adhesiveness is convenient when used after being pelletized, but when pelletizing is performed by cutting the strand into pellets, it becomes a large mass due to its own weight (blocking), On the other hand, usability may be impaired.

  Conventionally, as a method for preventing blocking, after pelletizing, pellets are coated with fine talc powder, or an oil-based release agent is applied to strands before pelletizing.

  However, in the method of coating pellets with talc fine powder after pelletizing, talc fine powder is likely to rise and the workability in the factory is impaired, and adhesion of talc fine powder to the pellet tends to be uneven. There was a problem that it was relatively difficult to ensure stable quality. In addition, when the amount of talc fine powder attached becomes excessive or when foreign matter is mixed in when talc fine powder is attached, the quality of the hot melt for molding may be significantly impaired. In addition, there was a problem that the workability at the time of pelletizing was impaired due to sticking to the cutter during pelletizing, winding around inside the pelletizer, or forming a lump.

  In addition, the method of applying an oil-based mold release agent to the strand before pelletizing did not impair the workability during pelletizing, but blocking was prevented when a load was applied over a long period of time, such as in a shipping service. There was a problem that it could not be performed, and a problem that the adhesiveness of the molding hot melt was lowered by the oil-based release agent.

JP 2004-210893 A JP 2007-070444 A

  Therefore, the present invention provides a method for pelletizing a polyester-based molding resin composition having good workability at the time of pelletizing processing and that does not cause blocking after the pelletizing processing, and a polyester system produced by the method. It is an object to provide pellets of a molding resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have found that the aromatic polyester (a), the tackifier (b), and the polyol compound (c) having two or more hydroxy groups in one molecule. And a strand of a polyester-based molding resin composition containing a polyolefin (d) having a polar group is extruded and cooled, and the polyolefin resin fine particles having a dropping point of 100 ° C. or higher and an average particle diameter of 80 μm or less are obtained. It was learned that when the strand was attached to the surface of the strand and the strand was cut and pelletized, the workability at the time of pelletizing was good and blocking after pelletizing did not occur, and the present invention was completed.

That is, the present invention provides the following (1) to (5).
(1) A polyester system containing an aromatic polyester (a), a tackifier (b), a polyol compound (c) having two or more hydroxy groups in one molecule, and a polyolefin (d) having a polar group A method for pelletizing a resin composition for molding,
A step of extruding a strand of the molding resin composition;
Cooling the strand;
A pelletizing method comprising: a step of adhering polyolefin resin fine particles having a dropping point of 100 ° C. or higher and an average particle size of 80 μm or less to the surface of the strand; and a step of cutting the strand into pellets.
(2) The aromatic polyester (a) is
Polyester A obtained by reacting an acid component composed of terephthalic acid and isophthalic acid with a hydroxy group component composed of 1,4-butanediol and polyoxytetramethylene glycol; an acid component composed of terephthalic acid and isophthalic acid; Polyester B obtained by reacting a hydroxy group component consisting of 1,4-butanediol and ε-caprolactone, an acid component consisting of terephthalic acid and isophthalic acid, neopentyl glycol, ethylene glycol and 1,4-butanediol Polyester C obtained by reacting a hydroxy group component comprising: a polyester C obtained by reacting with a hydroxy group component; an acid component comprising terephthalic acid and isophthalic acid; and a hydroxy group component comprising neopentyl glycol and ethylene glycol. And, containing,
The polyester A is 10 to 50% by mass, the polyester B is 30% by mass or less, the polyester C is 30% by mass or less, and the polyester D is contained at a content of 10 to 50% by mass. Pelletizing method.
(3) The pelletize according to (1) or (2), wherein the polyolefin (d) is contained in an amount of 5 to 40% by mass based on the total mass of the aromatic polyester (a) and the polyolefin (d). Processing method.
(4) A polyester molding resin composition pellet obtained by the pelletizing method according to any one of (1) to (3) above.
(5) A component having a sealing portion that is hot-melt molded using the pellet according to (4).

  According to the present invention, there is good workability at the time of pelletizing, and there is no blocking after the pelletizing process, and the polyester molding resin composition produced by the method and the method of pelletizing a resin composition for polyester-based molding having tackiness A pellet of the molding resin composition is provided.

  Further, the pellets of the polyester-based molding resin composition produced by the pelletizing method of the present invention are not easily blocked even when a long-term load is applied, and the usability is not impaired. Furthermore, the adhesiveness can be maintained without being separated even after melting for a long time. Moreover, the adhesiveness with respect to polyolefin can be improved, maintaining the outstanding characteristics, such as the adhesiveness with respect to a metal and PVC, and gasoline resistance.

  In addition, a component having a sealing portion hot-melt molded using pellets of a polyester-based molding resin composition produced by the pelletizing method of the present invention can be molded at a relatively low temperature and low pressure. Since the entire structure can be waterproofed and there is no need to provide an atmosphere opening portion for preventing moisture from entering unlike conventional products, there are few restrictions on the design, and the mass production is low at low cost.

The pelletizing method of the present invention has the following advantages because blocking is less likely to occur.
-Since it is not necessary to break up the lump when using pellets, the time and effort during use can be reduced.
-If blocked, only a tank-type melter can be used, but if not blocked, it can be used in a melting extruder as needed.

The ability to use an extruder that can be melted at any time can eliminate the following tank-type defects, so that hot melt can be used stably while reducing costs.
・ It takes time to melt in the tank type.
-After melting, there is a high possibility of being left in a molten state until use for a long time, and the difference in physical properties between those melted in the initial stage and those melted for a long time tends to increase.
・ If there is an unused part of the melted material, it will be remelted and the physical properties are likely to deteriorate. Therefore, measures such as discarding the unused part are necessary and wasteful.
・ Since there is something that stays in the corner of the tank, there is a great risk that the physical properties will not be stable.

FIG. 1 is a diagram schematically showing the pelletizing method of the present invention. 2A and 2B are a perspective view and a cross-sectional view, respectively, showing an adhesion test with PP. FIG. 3 is a view showing a conventional harness. FIG. 4 is a view showing a conventional connector. FIG. 5 is a diagram schematically showing a conventional pelletizing method (unmeasured). FIG. 6 is a diagram schematically showing a conventional pelletizing method (attachment of fine talc powder). FIG. 7 is a diagram schematically illustrating a conventional pelletizing method (attachment of an emulsion of a polyester resin or an oil-based release agent).

1. Pelletizing method of polyester molding resin composition (1) Polyester molding resin composition Polyester molding resin composition comprises aromatic polyester (a), tackifier (b), and hydroxy in one molecule. If it contains the polyol compound which has 2 or more groups, and polyolefin (d) which has a polar group, it will not specifically limit.

<Aromatic polyester (a)>
The aromatic polyester (a) is not particularly limited, and any known aromatic polyester can be used without particular limitation, and among them, an aromatic polyester obtained from a condensation reaction between a fatty acid and a glycol is preferable.
Specific examples of the aromatic polyester (a) include, for example, an acid component containing terephthalic acid and / or isophthalic acid, ethylene glycol (hereinafter abbreviated as EG), polytetramethylene ether glycol (hereinafter referred to as PTMG). A hydroxy group component containing at least one selected from the group consisting of neopentyl glycol (hereinafter abbreviated as NPG) and 1,4-butanediol (hereinafter abbreviated as 1,4-BD). Aromatic polyesters containing polyester obtained by reaction are mentioned, and more specifically, aromatic polyesters containing polyesters A to D shown below are preferred.

The polyester A is a polyester obtained by a condensation reaction using a mixture of terephthalic acid and isophthalic acid as an acid component and using a mixture of PTMG and 1,4-BD as a hydroxy group component.
The PTMG is not particularly limited as long as it is a polymer obtained by polymerizing 1,4-BD, but preferably has a number average molecular weight of 2000 or more.
Specifically, as the polyester A, for example, Hytrel 4057 (manufactured by Toray DuPont) or the like can be used.

The polyester B is a polyester obtained by a condensation reaction using a mixture of terephthalic acid, isophthalic acid and ε-caprolactone as the acid component and 1,4-BD as the hydroxy group component.
Specifically, for example, Elitel UE3800 (manufactured by Unitika) or the like can be used as the polyester B.

The polyester C is a polyester obtained by a condensation reaction using a mixture of terephthalic acid and isophthalic acid as an acid component and 1,4-BD, NPG and EG as a hydroxy group component.
Specifically, for example, Elitel UE3510 (manufactured by Unitika) or the like can be used as the polyester C.

  The polyester D is a polyester obtained by a condensation reaction using a mixture of terephthalic acid and isophthalic acid as the acid component and using a mixture of NPG and EG as the hydroxy group component.

  The aromatic polyester (a) preferably contains at least two selected from the group consisting of the polyesters A, B, C and D, and contains the polyester A and the polyester D. Is more preferable. This is a molding resin composition obtained by containing 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 is kept low and the solidified product after molding is given flexibility. For the same reason, the aromatic polyester (a) preferably contains the polyester A and the polyester D and the polyester C and / or the polyester B.

  The content ratio of the polyesters A, B, C, and D in the aromatic polyester (a) is 10 to 50% by mass of the polyester A and the polyester B with respect to the total mass of the aromatic polyester (a). It is preferable to contain 0-30 mass%, the polyester C 0-30 mass%, and the polyester D 10-50 mass%, the polyester A 20-40 mass%, and the polyester B 0-25. More preferably, the polyester D is contained in an amount of 25 to 45% by mass, the polyester C is contained in an amount of 0 to 20% by mass, the polyester A in an amount of 25 to 35% by mass, and the polyester B in an amount of 0 to 20% by mass. More preferably, the polyester D is contained in an amount of 30 to 40% by mass and the polyester C is contained in an amount of 0 to 15% by mass.

  When the content ratios of the polyesters A, B, C, and D are 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 molding resin composition obtained. In addition, a 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. In addition, the polyester-based molding resin composition having such properties is excellent in heat shock resistance and can follow the expansion and contraction of the adherend during the heat cycle, so that it can be used as a hot melt material for molding. It is preferable to use it.

<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 or orange peel contained in pine, and specifically, terpene resins, aromatic modified terpene resins, terpene phenol resins. A hydrogenated terpene resin or the like is preferably exemplified.

  Examples of the petroleum resin-based tackifier include aliphatic, alicyclic, and aromatic resins made from petroleum, specifically, C5 petroleum resins, C9 petroleum resins, and 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.
From the reason that the stretchability of the resulting moldable resin composition, the adhesion to polyolefin, metal and PVC is improved, and further the balance between heat resistance and flexibility, and the gasoline resistance is good, It is preferable to use rosin diol which is a rosin ester.
Specific examples of the rosin diol include Pine Crystal D-6011, KE-615-3, D-6240 (all manufactured by Arakawa Chemical Industries, Ltd.) and the like.

  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) having two or more hydroxy groups in one molecule>
The polyol compound (c) having two or more hydroxy groups in one molecule (hereinafter sometimes simply referred to as “polyol compound (c)”) is a polyol compound having two or more hydroxy groups in one molecule. And it will not specifically limit if it acts as a compatibilizer which makes the said aromatic polyester (a) and the said tackifier (b) compatible, Specifically, for example, ethylene glycol, propylene glycol, butane Diol, polycarbonate diol, polycaprolactone, diethylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol and the like, and further, polytetramethylene ether glycol, polyethylene glycol, polypropylene glycol, polyoxypropylene diol, Polyether polyols such as polyoxypropylene glycol such as reoxypropylene triol; Polyolefin polyols such as polybutanediene polyol and polyisoprene glycol; Adipate polyols; Lactone polyols; Polyhydric alcohols such as polyester polyols such as castor oil Polyhydric phenols such as resorcin and bisphenol 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 compatibilizing agent can be obtained with a small amount, and it is more preferable to use polycarbonate diol because it is excellent in 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 polyester-based molding resin composition 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 is improved. And the balance of flexibility, and 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, decreases when the tackifier (b) is added alone. Property is improved. 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) having polar group>
The polyolefin (d) having the polar group (hereinafter, sometimes simply referred to as “polyolefin (d)”) is not particularly limited, and specifically, for example, ethylene, propylene, butylene, pentene, 4-methyl From homopolymers of α-olefins such as -1-pentene, copolymers of two or more of these α-olefins, or copolymers of these α-olefins with other copolymerizable monomers And a polyolefin resin having a polar group introduced into its main chain and / or side chain. These may be used alone or in combination of two or more. As the α-olefin homopolymer, polyethylene is preferred because it is more excellent in gasoline resistance.

  The polar group is not particularly limited, and specifically, for example, epoxy group (including glycidyl group), carboxy group, acid anhydride group, amino group, isocyanate group, hydroxy group, nitro group, sulfone group Etc. 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 (including a glycidyl group), a carboxy group, and an acid anhydride group from the viewpoint of excellent adhesion to polar substances, and more preferably an epoxy group. preferable.
The polyolefin (d) preferably has an epoxy group and a carboxy group and / 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.

In general, polyolefin has low polarity, so it has poor compatibility with aromatic polyesters with high polarity. If a composition containing these is melted for a long time during or after production, the aromatic polyester and polyolefin May be separated and may not be sufficiently mixed even if stirred again, resulting in a decrease in adhesiveness. However, since the polyester-based molding resin composition uses the aromatic polyester (a) and the polyolefin (d) having a polar group, the polyester-based molding resin composition does not separate even after being melted for a long time and can maintain adhesiveness.
In addition, since the polyolefin (d) is contained, the adhesiveness can be maintained even when an anti-adhesive agent composed of polyolefin resin fine particles is adhered to the pellet.

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

  Specific examples of the polyolefin (d) include, for example, Bond Fast 2C, E (above, ethylene-glycidyl methacrylate copolymer), 2B, 7B (above, ethylene-glycidyl methacrylate-vinyl acetate), 7L, 7M. (Ethylene-glycidyl methacrylate-methyl acrylate) or the like (both manufactured by Sumitomo Chemical Co., Ltd.) is preferably used.

Although content of the said polyolefin (d) is not specifically limited, It is preferable that it 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). When the polyolefin (d) is contained in this range, the balance between the adhesion to polyolefin and the adhesion to metal and PVC is further excellent, and the gasoline resistance is also excellent.
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 polyester-based molding resin composition contains the polyolefin (d) in a specific ratio, the adhesion to polyolefin is improved while maintaining excellent properties such as adhesion to metals and PVC and gasoline resistance. can do. Moreover, the adhesiveness can be maintained without separation even after melting for a long time.

  The polyester-based molding resin composition may be a reinforcing agent, an anti-aging agent, an antioxidant, a filler, a plasticizer, or a heat stabilizer, if necessary, as long as the object of the present invention is not impaired. In addition to UV absorbers and other lubricants, waxes, colorants, crystallization accelerators, reinforcing fibers and other various additives may be blended.

  The manufacturing method of the said polyester-type molding resin composition is not specifically limited, The said aromatic polyester (a), the said tack fire (b), the said polyol compound (c), the said polyolefin (d), and as needed Various additives can be produced by mixing with, for example, a roll, a kneader, an extruder, a universal stirrer, or the like.

  The polyester-based molding resin composition 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.

(2) Pelletizing method The pelletizing method of the present invention includes the following steps.
B) Extrusion molding step This is a step of producing a strand of the polyester molding resin composition by extruding the molten polyester molding resin composition.
The method of extrusion molding is not particularly limited, and a conventionally practiced method can be used.

B) Cooling step This is a step of cooling the strands produced by extrusion molding.
The method of cooling is not particularly limited, and a conventionally practiced method can be used.
The cooling method may be air cooling or liquid cooling. For example, it is preferable to continuously cool the strand by immersing the strand in cooling water in a water tank (cooling water tank) containing cooling water.

C) Adhesion step This is a step of adhering fine particles of olefin resin to the surface of the cooled strand.
The attachment method is not particularly limited, and various methods that can be carried out by those skilled in the art can be used. For example, the strand may be passed through a release agent tank containing polyolefin resin fine particles, and the polyolefin resin fine particles may be adhered to the surface of the strand.

  The polyolefin resin fine particles (hereinafter sometimes simply referred to as “fine particles”) are polyolefin resin fine particles having a dropping point of 100 ° C. or higher and an average particle diameter of 80 μm or less, and are not particularly limited.

  The polyolefin resin is not particularly limited, and specifically, for example, homopolymers of α-olefins such as ethylene, propylene, butylene, pentene, 4-methyl-1-pentene, and 2 of these α-olefins. Examples thereof include a copolymer composed of at least species, 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 resin may have a polar group. The said polar group is not specifically limited, What was described in the item of the said polyolefin (d) etc. are mentioned. The polyolefin (d) may have only one of these functional groups or may have a plurality of types of functional groups.

  In addition to the polyolefin-based resin, the fine particles may optionally contain reinforcing agents, anti-aging agents, antioxidants, fillers, plasticizers, heat stabilizers, UV absorbers and other lubricants, waxes, and coloring. Various additives such as an agent, a crystallization accelerator, and a reinforcing fiber may be blended.

The dropping point of the fine particles refers to the dropping point of the fine particles of the polyolefin resin and is 100 ° C. or higher, preferably 100 to 200 ° C., more preferably 120 to 150 ° C.
Here, the dropping point is a temperature at which the sample of the polyolefin resin fine particles is heated from a semi-solid state to a liquid when heated in a prescribed condition, and drops from the sample cup, for example, according to ASTM D3945 standard. It can be measured by a drop point measurement test. The dropping point is a concept different from the melting point.

The average particle diameter of the fine particles is 80 μm or less, preferably within the range of 1 to 80 μm, more preferably within the range of 1 to 60 μm, further preferably within the range of 1 to 50 μm, and within the range of 1 to 20 μm. Even more preferable.
In this specification, the “average particle size” means a particle size at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method. For example, using a laser diffraction / scattering type particle size distribution measuring device. It can be measured.
The method for measuring the average particle diameter is not particularly limited as long as the particle diameter at the integrated value 50% in the particle size distribution obtained by the laser diffraction / scattering method is obtained. Specifically, for example, In a container such as a glass Erlenmeyer flask (500 mL capacity), a certain amount (about 10 mg to 5 g, appropriately changed according to the sample) of fine particles is added, and 2 to 3 drops of emulsifier (ARKOPAL® N 090, manufactured by Clariant ⁾ CAS # 9062-77-5) After adding an aqueous solution and stirring well, a certain amount of water (about 200 mL) is added, and sonication is performed for about 5 minutes to disperse the fine particles. Using as a sample, it can be measured by a laser diffraction / scattering type particle size distribution measuring apparatus (LA-920 manufactured by Horiba, Ltd.).

D) Cutting step This is a step of cutting the strand of the polyester-based molding resin composition into pellets.
The strand can be cut and pelletized by a conventionally known method. For example, the strand can be pelletized by cutting the strand with a cutter at a desired length using a pelletizer. Although a cutter is not specifically limited, From a viewpoint of productivity, rotary cutters, such as a rotary cutter and a fan cutter, are preferable.

  According to the method of the present invention, the polyolefin resin fine particles are adhered to the strand surface and pelletized, so that the polyolefin resin fine particles adhere to the cut surface, and can prevent adhesion and blocking to the cutter. There is no loss of productivity.

The pelletizing method of the present invention may include the following steps as desired.
E) Drying step This is the step of drying the pellets. The drying method is not particularly limited, and various methods that can be carried out by those skilled in the art can be used. For example, drying may be performed with hot air of less than 40 ° C.

2. Pellet of polyester molding resin composition The pellet produced by the pelletizing method of the present invention applies the extrusion molding process, the cooling process, the adhesion process and the cutting process to the polyester molding resin composition. It is a pellet manufactured by doing.

3. Parts having hot-melt molded sealing parts Pellets produced by the pelletizing method of the present invention are prevented from blocking, which makes it difficult for the pellets to adhere and take out in a container during storage. And it does not stick in the hopper and does not become difficult to move to the applicator.

  The polyester molding resin composition is excellent in adhesion to polyolefin, metal and PVC, gasoline resistance, stretchability, flexibility and the like. In addition, it has low viscosity and excellent moldability. In particular, since 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.

  In addition, the polyester-based molding resin composition is useful as a sealant / waterproof protectant for end portions of connectors / harnesses, etc. It is also useful as a material (a filler embedded in the entire electric circuit in order to protect the electric circuit from impact, vibration or moisture).

  The method for producing a waterproof protective coating using the above polyester-based molding resin composition is a method for producing a waterproof protective coating in which a waterproof protective coating is formed on the edge of an electronic device using the above-described molding resin composition of the present invention. There is a melting step for melting the molding resin composition of the present invention, and a discharge molding for applying or molding the molten molding resin composition after the melting step to the end of the electronic device at a pressure of less than 5 MPa. It is a manufacturing method of the waterproof protective coating characterized by comprising an application | coating process. 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 polyester-based molding resin composition, and specifically, a step of heating and melting the moldable resin composition at 160 to 230 ° C., preferably 180 to 210 ° C. It is.

  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 the pressure is 0 when the method for producing a waterproof protective coating using the polyester molding resin composition is used. It is excellent because it can be used at a melting temperature of 180 to 230 ° C. Therefore, it is preferable to use the above-described manufacturing method because molding at such a low temperature and low pressure is possible, so that the cost for molding can be reduced. Specifically, the entire substrate can be waterproofed, and it is not necessary to cover the substrate and electronic components with a case like a one-pack type silicone resin composition, which is preferable because the cost of the product can be reduced. .

  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, if the above polyester-based molding resin composition is used, the curing time after molding is as follows. It is preferable because it can be completed by natural cooling in several seconds to several tens of seconds and can be released from the mold within several minutes. Specifically, if the above polyester-based molding resin composition is used, the injection time of the HM material for molding is completed in 10 seconds, and it is possible to release from the mold within 1 minute by natural cooling. Therefore, it is preferable. 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, etc. 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, if the waterproof protective coating manufactured by the above-described method is used, the conductor is cut in the middle as in the past or the atmosphere Since there is no need to provide an open portion or the like, it is preferable because it is not subject to regulations such as design, is low cost, and is excellent in mass productivity.

[Manufacture of resin composition for molding]
About each Example and each comparative example, each component was mixed with the compounding quantity (mass part) shown in Table 1, and the resin composition for shaping | molding was manufactured.

In Table 1, each component is as follows.
(1) Polyesters A to D
・ Polyester A: Hytrel 4057 (manufactured by Toray DuPont)
Polyester C: Elitel UE-3510 (manufactured by Unitika)
-Polyester D: Elitel UE-3320 (manufactured by Unitika)
(2) Rosin tackifier Pine crystal KE-6011 (Arakawa Chemical Industries)
(3) Polycarbonate diol PLACCEL CD220 (manufactured by Daicel Chemical Industries)
(4) Polyethylene bond first 7L having an epoxy group (manufactured by Sumitomo Chemical Co., Ltd.)
(5) Low density polyethylene Sumikasen G807 (Sumitomo Chemical Co., Ltd.)
(6) Hindered phenol-based anti-aging agent Irganox 1010 (Ciba Specialty Chemicals)
2. Anti-adhesive agent / PO1: polyolefin resin fine particles (drop point 145 ° C., average particle size 20 μm; Celidust 6050M, manufactured by Clariant)
PO2: polyolefin resin fine particles (drop point 125 ° C., average particle size 15 μm; Celidust 130, manufactured by Clariant)
PO3: polyolefin resin fine particles (dropping point 110 ° C., average particle size 10 μm; Celidust 3715, manufactured by Clariant)
PO4: polyolefin resin fine particles (dropping point 73 ° C., average particle size 10 μm; Celidust 8020, manufactured by Clariant)
product name )
・ Talc 1: Talc powder (average particle size 5 μm; Microace P-3, manufactured by Nihon Talc)
Em1: Polyester resin emulsion (resin solid content: 30% by mass, Tg = 67 ° C., Mw = 8500; Elitel KA-5071S, manufactured by Unitika)
・ Oil 1: Fat and oil release agent (Mold E50, manufactured by Yushi Co., Ltd.)

[Manufacture of pellets]
(1) Examples 1-6, Comparative Examples 1-5, 10 (see FIG. 1)
The strand 1 of the resin composition for molding is extruded, cooled by being immersed in cooling water in the cooling water tank 2, the polyolefin resin fine particles 4 are adhered in the release agent tank 3, and the pellet 8 is cut by the pelletizer 7. Obtained.
(2) Comparative Example 6 (see FIG. 5)
The strand 1 of the molding resin composition was extrusion-molded, immersed in cooling water in the cooling water tank 2 to be cooled, and cut with a pelletizer 7 to obtain pellets 8.
(3) Comparative Example 7 (see FIG. 6)
The strand 1 of the molding resin composition is extruded, cooled in a cooling water tank 2 by immersing it in cooling water, cut with a pelletizer 7 to form pellets 8, and talc fine powder 5 is adhered to the surface of the mold release agent tank 3 And pellets 9 pulverized with fine talc powder were obtained.
(4) Comparative examples 8 and 9 (see FIG. 7)
The strand 1 of the molding resin composition is extruded, cooled in a cooling water tank 2 by immersing it in cooling water, a polyester resin emulsion or an oil-based release agent 6 is adhered in a release agent tank 3, and a pelletizer 7 is used. The pellet 8 was obtained by cutting.

[Melting test (state at the time of melting)]
The produced pellets were put in a container and allowed to stand at 200 ° C. for 72 hours and then cooled.
After cooling, the hot melt mass was removed and cut in half.
The cut surface was observed and evaluated as “x” if the components were separated and “◯” if the components were not separated.
A performance test was conducted only for those with an evaluation of “◯”.
For those with an evaluation of “x”, the performance test was not performed, and “ND” was described in the evaluation column of Table 1.

[Performance test method]
<Workability>
The workability in the factory was evaluated by whether or not the strands or pellets adhered to the cutter and whether or not the talc dust soared. That is, under the following conditions, the case where the strand or pellet did not adhere to the cutter and the talc dust did not fly up was evaluated as acceptable, and the case other than this was evaluated as unacceptable. The results are shown in Table 1 as “◯” for pass and “x” for fail.
The conditions are as follows.
<< normal temperature >> temperature (temperature) 20 ℃, humidity 50% RH
《High temperature》 Air temperature (temperature) 35 ℃, humidity 85% RH

<Blocking resistance>
Under the following conditions, when blocking did not occur, it was evaluated as acceptable, and when it occurred, it was evaluated as failed. The results are shown in Table 1 as “◯” for pass and “x” for fail.
<Short term (room temperature)> After drying the produced pellets at 50 ° C. for 24 hours, put 50 g in a cup, place a weight on the top so that it is 14 g / cm ² or more, and blocking occurs after 24 hours at room temperature. Observed whether or not.
<< Long-term (40 ° C) >> After drying the produced pellets at 50 ° C. for 24 hours, 50 g is put in a cup, and a weight is placed on the upper part so that it is about 40 g / cm ² or more. It was observed whether blocking occurred.
<Long-term (80 ° C.)> After drying the produced pellets at 50 ° C. for 24 hours, 100 g is put into a cup, and a weight is placed on the top so that it is about 40 g / cm ^2. It was observed whether blocking occurred.

<Adhesiveness>
The adhesion to polyolefin resin was evaluated in accordance with JIS K 6256-2: 2006 (90 ° peel strength with rigid plate). A 2 mm thick corona surface-treated polypropylene sheet (Kobe Poly Sheet PP-N-BN, manufactured by Shin-Kobe Electric Machinery Co., Ltd.) was cut into 25 mm × 150 mm and used as a PP test piece. The produced molding resin composition is molded on this PP test piece as shown in FIG. 2 using a mold, and a 90 ° peeling test is performed so that the molding resin composition 41 is peeled off from the PP test piece 42. The maximum tensile stress when the PP test piece 42 and the molding resin composition 41 began to peel off was measured. The tensile speed was 50 mm / min. Those having a maximum tensile stress of 50 N / 25 mm or more were evaluated as acceptable, and others were evaluated as unacceptable. The results are shown in Table 1 as “◯” for pass and “x” for fail.

<Property growth>
The maximum elongation at break was measured according to JIS K 6251: 2004. Those having an elongation of 300% or more were evaluated as acceptable, and others were evaluated as unacceptable. The results are shown in Table 1 as “◯” for pass and “x” for fail.

<Surface feel>
The surface of the molding resin composition after being melted and solidified was touched with a finger, and those that did not feel strange such as stickiness and sliminess were passed, and some were rejected. The results are shown in Table 1 as “◯” for pass and “x” for fail.

<Judgment>
Those in which the evaluation of the melting test was “x” was judged as unacceptable.
Those with a melt test evaluation of “◯” are those that have been evaluated as acceptable for workability, blocking resistance, adhesiveness, physical property elongation, and surface feel, and that have at least one failure. It was determined to be rejected.
The results are shown in Table 1 as “◯” for pass and “x” for fail.

DESCRIPTION OF SYMBOLS 1 Strand of resin composition for molding 2 Cooling water tank 3 Mold release agent tank 4 Fine particle of polyolefin resin 5 Talc fine powder 6 Emulsion of polyester resin or oil-based release agent 7 Pelletizer 8 Pellet 9 Powdered with talc fine powder Pellet 41 Molding resin composition 42 PP test piece 50 Harness 51 Caulking portion 52 Joining portion 53 Conductive wire 54 Air release portion 60 Connector 61 Molding portion 62 Joining portion 63 Conducting wire

Claims (5)

Polyester molding resin containing aromatic polyester (a), tackifier (b), polyol compound (c) having two or more hydroxy groups in one molecule, and polyolefin (d) having a polar group A method for pelletizing a composition comprising:
A step of extruding a strand of the molding resin composition;
Cooling the strand;
A pelletizing method comprising: a step of adhering polyolefin resin fine particles having a dropping point of 100 ° C. or higher and an average particle size of 80 μm or less to the surface of the strand; and a step of cutting the strand into pellets. The aromatic polyester (a) is
Polyester A obtained by reacting an acid component composed of terephthalic acid and isophthalic acid with a hydroxy group component composed of 1,4-butanediol and polyoxytetramethylene glycol; an acid component composed of terephthalic acid and isophthalic acid; Polyester B obtained by reacting a hydroxy group component consisting of 1,4-butanediol and ε-caprolactone, an acid component consisting of terephthalic acid and isophthalic acid, neopentyl glycol, ethylene glycol and 1,4-butanediol Polyester C obtained by reacting a hydroxy group component comprising: a polyester C obtained by reacting with a hydroxy group component; an acid component comprising terephthalic acid and isophthalic acid; and a hydroxy group component comprising neopentyl glycol and ethylene glycol. And, containing,
The pelletize according to claim 1, comprising 10-50% by mass of the polyester A, 30% by mass or less of the polyester B, 30% by mass or less of the polyester C and 10-50% by mass of the polyester D. Processing method.   The pelletizing method according to claim 1 or 2, wherein the polyolefin (d) is contained in an amount of 5 to 40% by mass based on the total mass of the aromatic polyester (a) and the polyolefin (d).   The pellet of the resin composition for polyester type | molds obtained by the pelletizing processing method in any one of Claims 1-3.   The component which has a sealing part hot-melt-molded using the pellet of Claim 4.