JP4632513B2

JP4632513B2 - Molding method of vulcanized rubber grounding bottom for injection molded shoe sole

Info

Publication number: JP4632513B2
Application number: JP2000317255A
Authority: JP
Inventors: 塚本孝二; 横山隆宏; 上野啓; 廣田知文
Original assignee: 株式会社アサヒコーポレーション
Priority date: 2000-10-18
Filing date: 2000-10-18
Publication date: 2011-02-16
Anticipated expiration: 2020-10-18
Also published as: JP2002119307A

Description

【０００１】
【産業上の利用分野】
この発明は、射出成形靴底の接地面にインサート成形するための射出成形靴底用加硫ゴム接地底の成形法に関するものである。
【０００２】
【従来の技術】
射出成形ポリウレタン靴底は軽量で耐摩耗性に優れている反面、防滑性、耐亀裂性に欠けるため、接地面に加硫ゴムで形成された接地底をインサート成形したポリウレタン靴底が、スポーツシューズ、作業靴、婦人靴、紳士靴等の靴底として幅広く使用されている。ポリウレタンと加硫ゴムは接着性に乏しいため、インサート用の加硫ゴム接地底の上面、即ちウレタン靴底本体との接着面をバッフイングし、さらにハロゲン処理してからウレタン系接着剤を塗布して、これをインサート成形していた。他方加硫ゴム接地底の上面に布や不織布を一体に積層成形し、この不織布に靴底成形時にウレタンを浸透させて、ゴム接地底をインサート成形する方法も行われていた。
しかしながら前者は成形工程が煩雑でコストアップの原因となっていた。また後者は接地底成形に際して、未加硫ゴムの上面に不織布を重ねてこれを成形型で加熱加圧加硫する場合、不織布が薄肉な場合、成形時に未加硫ゴムが布や不織布の組織中に投錨一体化すると共にその表面に露出して、これが加硫ゴムの皮膜を形成し、ポリウレタン靴底本体にインサート成形する場合、この加硫ゴム皮膜によってポリウレタン靴底本体との接着性を著しく阻害していた。したがってインサート成形に先立って前者と同様に接地底の表面に露出された加硫ゴム皮膜をバフィングによって除去したり、その表面に接着剤を塗布乾燥しておかねばならず、作業が煩雑でコストアップの原因となっていた。このため厚みが１〜３mmの厚肉で密度の高い不織布が使用されていたが、接地底成形時における不織布に対する未加硫ゴムの投錨が不充分で、不織布が層間剥離をおこし、接地底と靴底本体との接着性に問題があった。
【０００３】
【発明の課題】
この発明はポリウレタン、ＰＶＣ、熱可塑性エラストマーからなる射出成形靴底にインサート成形する場合、接着剤を塗布する必要がなく、しかも射出成形される靴底本体との接着性に優れた接地底を備えた靴底を廉価に提供しようとするものである。
【０００４】
【課題を解決するための手段】
この発明は、融点が加硫温度±２０℃の範囲内の熱接着性の合成樹脂乃至繊維からなる芯層２３の上下に融点が２００℃以上の上層繊維布２１と下層繊維布２２を積層すると共に該芯層２３をオレフィン系のフラットヤーン布で構成し、芯層２３を介して上下繊維２２．２３を構成する繊維ウェブを交絡した上貼り布２を未加硫ゴムからなる接地底成形材１１の上面に重ね、これを１４０〜１８０℃で加熱加圧して加硫ゴム接地底１を成形するとともに、接地底成形材１１の一部をこれと接する上張り布２の下方に積層された下層繊維布２２の組織間隙に投錨一体化させ、且つ芯層２３を軟化乃至溶融させてこれをその上下に積層された上下層繊維布２１．２２に接着させることを特徴とする射出成形靴底用加硫ゴム接地底の成形法を発明の要旨とするものである。
【０００５】
この発明において、上張り布２を構成する上層繊維布２１と下層繊維布２２は融点が、加硫温度にもよるが１９０℃以上の織布、編布、不織布などの布帛であって、木綿等の天然繊維、レーヨン、アセテート等の再生乃至半合成繊維、ビニロン、ナイロン６６、ポリエステル、アクリル、ポリウレタン等の合成繊維の1種又は2種以上の混合物で構成されている。そして熱接着性の合成樹脂からなる芯層23は接地底の加硫温度にもよるが、通常ゴム底の加硫温度は１４０〜１６０℃に設定されているのでポリプロピレン、ポリエチレン等のポリオレフィン系合成樹脂フイルム、フラットヤーン織布、またはこれらの合成繊維布のような融点が１２０〜１８０℃低融点の接着性合成樹脂乃至繊維布で構成されることが好ましい。この発明においてこれらの低融点合成樹脂ないし繊維からなる芯層２３は融点が加硫温度以下であっても加硫時の加圧によって軟化されて上張り布を構成する上下層繊維布２１．２２の組織間隙に圧入され界面で上下層繊維布２１．２２との接着性を示すものである。芯層23を構成する合成樹脂乃至繊維の融点がそれ以下となれば、芯層２３は上下繊維布２１．２２を介して間接的に成形型で加熱されることになるが、芯層23が加硫の初期に完全に溶融してしまい、下層繊維布２２に投錨される接地底成形材１１の投錨圧で溶融された芯層２３が上張り布２の上面に染み出してしまい、靴底本体３との接着性が著しく阻害されるばかりではなく上張り布２の柔軟性が低下し靴底の屈曲性が阻害される惧れがあり、芯層23を構成する合成樹脂乃至繊維の融点がそれ以上となれば接地底成形時の加熱によつてによつて、芯層23を構成する合成樹脂乃至繊維を軟化乃至溶融させることが出来ず上張り布の上下層繊維布２１．２２を接着固定できず層間剥離し易くなるから好ましくない。この発明において芯層23をオレフィン系のフラットヤーン布で構成しこの上下に融点が１９０℃以上の繊維ウェブをかさね、芯層23を介してニードルパンチによって上下層繊維布２１．２２を構成する繊維ウエブを交絡させたものを使用すれば、接地底成形時の加熱によって軟化乃至溶融した接着性フラットヤンー布によって上下の交絡したウエブが芯部で接着されるとともにフラットヤーン布の組織間隙隣接するフラットヤーンの相互接着によって閉塞され、接地底成形時に接地底成形材１１が上張り布２の上面に染み出すことがない。
【０００６】
この発明において、接地底成材１１としてはNR、IR、ＢＲ、SBR、NBR、CR、EPT、EVA、EPDMの一種または二種以上の混合物を主成分としてこれに、架橋剤、架橋促進剤、架橋助剤、充填剤、安定剤、老化防止剤等の常用のゴム配合薬品が添加され、バンバリーミキサー、ヘンセルミキサー、ミキシングロール、ニーダー等の混合機によって均一に混合配合し、これをシーティングし適宜形状に秤量裁断したものが使用される。
【０００７】
このようにして準備された接地底成形材１１は、先ずシーティング裁断された未加硫ゴムを接地底成形モールドにセットし、その上に上張り布２を重ね常法によってプレス金型でプレスゲージ圧８０ｋｇｆ／ｃｍ^２〜１５０ｋｇｆ／ｃｍ^２で、１２０〜１６０℃で加熱加硫される。加硫工程の初期に接地底成形材が軟化され、加圧によってこれと接する上張り布２の下層繊維布２２の組織間隙中に投錨一体化され、且つ融点が加硫温度±２０℃の範囲内の熱接着性の合成樹脂乃至繊維からなる芯層２３を軟化させながら、芯層２３の上下に積層された上下層繊維布２２．２３を相互に接着する。そして接地底成形材１１の加硫が進行し硬化して投錨が遮断される。従って接地底成形材が上張り布２の上面に染み出すことがない。
このようにして成形した加硫ゴム接地底１を、必要により適宜形状に裁断して靴底本体射出成形時にモールドキャビティにセツトして、常法によってポリウレタン、ＰＶＣ、熱可塑性エラストマーからなる靴底本体成形材を射出して靴底本体３を成形すれば、靴底本体成形時に靴底本体成形材が上張り布２の上面、即ち成形される靴底本体３と接する上層繊維布２１の組織間隙に加圧投錨固化され、靴底本体３と加硫ゴム接地底１との接着が確保される。
【０００８】
【発明の効果】
以上のように、この発明によって成形された加硫ゴム接地底１は、接着剤を塗布する必要もなく、靴底本体射出成形時に靴底本体３に一体に接着され、靴底本体３との接着性に優れた加硫ゴム接地底１を備えた靴底が廉価に得られる。
【０００９】
【実施例】
上張り布２として融点が１６０℃のポリプロピレン製の厚み０．２ｍｍのフラットヤーン織布を芯層２３としてその上下に融点が２６０℃で上下合わせて４５０ｇ／m^２ポリエステル繊維ウェブを重ねてニードルパンチで上下の繊維ウエブからなる上下層繊維布２１と２２をを芯層２３を介して交絡させた厚み2ｍｍの不織布を、接地底形状に裁断して上張り布2を準備し準備し、これを接地底成形時に未加硫ゴム生地からなる接地底成形材１１の上面に重ねて常法によってこれを１６０℃で、プレスゲージ圧１００ｋｇｆ／ｃｍ^２で７分間加熱加圧してこの発明の加硫ゴム接地底１を成形した。このようにして成形した加硫ゴム接地底１を接着剤を塗布することなく、ポリウレタン靴底本体射出成形時に靴底成形型の底部にセットして常法によつて靴底成形キャビティに液状のポリウレタンからなる靴底本体成形材を射出導入してウレタン発泡靴底本体３を成形するとともに、踏み付け部と踵部接地面に一体に加硫ゴム接地底１をインサート成形した。このようにして成形された靴底は靴底の屈曲性が阻害されることなく。上張り布２も層間剥離することなく加硫ゴム接地底１と靴底本体３との接着性に優れた靴底が廉価に得られた。
【図面の簡単な説明】
【図１】接地底の成形状態を示す要部断面図である。
【図２】靴底の成形状態を示す要部断面図である。
【符号の説明】
１．加硫ゴム接地底、１１．．．接地底成形材、２．上張り布、２１．．．上層繊維布、２２．．．下層繊維布、２３．．．芯層、３．靴底本体[0001]
[Industrial application fields]
The present invention relates to a method for molding a vulcanized rubber grounding bottom for injection-molded shoe soles for insert molding on a grounding surface of an injection-molded shoe sole.
[0002]
[Prior art]
Injection molded polyurethane shoe soles are lightweight and have excellent wear resistance, but lack slip resistance and crack resistance. Therefore, polyurethane shoe soles with a ground contact sole formed of vulcanized rubber on the ground contact surface are sports shoes. It is widely used as soles for work shoes, women's shoes, men's shoes, etc. Since polyurethane and vulcanized rubber have poor adhesion, the upper surface of the vulcanized rubber grounding bottom for inserts, that is, the adhesive surface with the urethane shoe sole body is buffed, and further treated with halogen before applying urethane adhesive. This was insert molded. On the other hand, cloth and nonwoven fabric are integrally laminated on the upper surface of the vulcanized rubber grounding bottom, and urethane is infiltrated into the nonwoven fabric during shoe sole molding to insert-mold the rubber grounding bottom.
However, in the former, the molding process is complicated and causes a cost increase. In the latter case, when forming a grounded bottom, when a non-woven fabric is layered on the upper surface of the unvulcanized rubber and this is heated and pressure vulcanized with a mold, if the non-woven fabric is thin, the unvulcanized rubber is a fabric or non-woven fabric When it is thrown in and exposed to the surface, it forms a vulcanized rubber film, and when it is insert-molded into the polyurethane sole body, this vulcanized rubber film significantly increases the adhesion to the polyurethane sole body. It was inhibiting. Therefore, prior to insert molding, the vulcanized rubber film exposed to the surface of the ground contact bottom must be removed by buffing, or an adhesive must be applied and dried on the surface, as in the former, which is cumbersome and expensive. It was the cause. For this reason, a thick non-woven fabric with a thickness of 1 to 3 mm was used, but the unvulcanized rubber was not sufficiently thrown into the non-woven fabric at the time of ground contact molding, and the non-woven fabric caused delamination. There was a problem with the adhesion to the shoe sole body.
[0003]
[Problems of the Invention]
This invention has a grounding sole that is excellent in adhesiveness to the injection molded shoe sole body, without applying an adhesive when insert molding is performed on an injection molded shoe sole made of polyurethane, PVC, or thermoplastic elastomer. It is intended to provide an inexpensive shoe sole.
[0004]
[Means for Solving the Problems]
In the present invention, an upper fiber fabric 21 and a lower fiber fabric 22 having a melting point of 200 ° C. or higher are laminated on the upper and lower sides of a core layer 23 made of a heat-adhesive synthetic resin or fiber having a melting point within a range of vulcanization temperature ± 20 ° C. The core layer 23 is composed of an olefin-based flat yarn cloth, and the upper adhesive cloth 2 entangled with the fiber webs constituting the upper and lower fibers 22.23 via the core layer 23 is a grounded bottom molding material made of unvulcanized rubber. 11 is laminated on the upper surface of the resin 11 and heated and pressed at 140 to 180 ° C. to form the vulcanized rubber grounding bottom 1, and a part of the grounding bottom molding material 11 is laminated below the upper cloth 2 in contact therewith. An injection-molded shoe sole characterized by throwing and integrating into the tissue gap of the lower fiber cloth 22 and softening or melting the core layer 23 and bonding it to the upper and lower fiber cloths 21.22 laminated on the upper and lower sides. Invented a method for molding vulcanized rubber grounding bottoms It is an effect.
[0005]
In the present invention, the upper fiber fabric 21 and the lower fiber fabric 22 constituting the upper fabric 2 are fabrics such as woven fabric, knitted fabric, and non-woven fabric having a melting point of 190 ° C. or higher depending on the vulcanization temperature. Natural fibers such as rayon, regenerated or semi-synthetic fibers such as acetate, vinylon, nylon 66, synthetic fibers such as polyester, acrylic and polyurethane, or a mixture of two or more. The core layer 23 made of a heat-adhesive synthetic resin depends on the vulcanization temperature of the ground bottom, but usually the vulcanization temperature of the rubber bottom is set to 140 to 160 ° C., so that polyolefin-based synthetics such as polypropylene and polyethylene are used. It is preferable that the resin film, the flat yarn woven fabric, or a synthetic fiber cloth thereof is composed of an adhesive synthetic resin or fiber cloth having a low melting point of 120 to 180 ° C. In this invention, the core layer 23 made of these low melting point synthetic resins or fibers is softened by the pressure during vulcanization even if the melting point is not more than the vulcanization temperature, and the upper and lower layer fiber fabrics 21.22 constituting the upper fabric. It is press-fitted into the tissue gap and exhibits adhesiveness to the upper and lower fiber fabrics 21.22 at the interface. If the melting point of the synthetic resin or fiber constituting the core layer 23 is lower than that, the core layer 23 is indirectly heated by the mold through the upper and lower fiber cloths 21.22. The core layer 23 is completely melted at the initial stage of vulcanization, and melted by the throwing pressure of the ground bottom molding material 11 cast on the lower fiber cloth 22 oozes out on the upper surface of the upper cloth 2, and the shoe sole Not only the adhesiveness with the main body 3 is remarkably inhibited, but also the flexibility of the upholstery cloth 2 is lowered and the flexibility of the shoe sole may be obstructed, and the melting point of the synthetic resin or fiber constituting the core layer 23 If it is more than that, the synthetic resin or fiber constituting the core layer 23 cannot be softened or melted by heating at the time of forming the grounded bottom, and the upper and lower fiber cloths 21.22 of the upper cloth cannot be softened or melted. It is not preferable because it cannot be fixed by adhesion and is easily peeled off. In the present invention, the core layer 23 is made of an olefin-based flat yarn cloth, and a fiber web having a melting point of 190 ° C. or more is covered above and below the fiber, and the upper and lower layer fiber cloth 21.22 is formed by needle punch through the core layer 23. If a web entangled is used, the flat tangled web is bonded at the core by the adhesive flat yarn cloth softened or melted by heating at the time of ground contact molding, and the flat yarn adjacent to the tissue gap of the flat yarn cloth The grounding bottom molding material 11 does not ooze out to the upper surface of the upper cloth 2 at the time of grounding bottom molding.
[0006]
In this invention, the ground contact bottom material 11 is mainly composed of one or a mixture of two or more of NR, IR, BR, SBR, NBR, CR, EPT, EVA, and EPDM. Common rubber compounding chemicals such as auxiliaries, fillers, stabilizers, anti-aging agents, etc. are added, and mixed and blended uniformly by a mixer such as a Banbury mixer, Hensel mixer, mixing roll, kneader, etc. What was weighed and cut into a shape is used.
[0007]
In the grounded bottom molding material 11 thus prepared, first, the unvulcanized rubber sheeted and cut is set in a grounded bottom molding mold, and the upper cloth 2 is overlaid thereon by a press die using a press die. in pressure ^{^{80kgf / cm 2 ~150kgf / cm 2}} , it is heated and vulcanized at 120 to 160 ° C.. In the initial stage of the vulcanization process, the ground bottom molding material is softened, and is casted and integrated into the interstices of the lower fiber cloth 22 of the upper cloth 2 that is in contact with the pressurization. The upper and lower layer fiber fabrics 22.23 laminated on the upper and lower sides of the core layer 23 are bonded to each other while the core layer 23 made of the heat-adhesive synthetic resin or fiber is softened. Then, vulcanization of the grounded bottom molding material 11 proceeds and hardens, and the anchoring is blocked. Therefore, the grounded bottom molding material does not ooze out to the upper surface of the upper cloth 2.
The vulcanized rubber grounding bottom 1 thus molded is cut into an appropriate shape as necessary and set into a mold cavity at the time of injection molding of the shoe sole body, and a shoe sole body made of polyurethane, PVC, or thermoplastic elastomer by a conventional method. If the shoe sole body 3 is molded by injecting the molding material, the shoe sole body molding material is formed on the upper surface of the upper fabric 2, that is, the tissue gap of the upper fiber cloth 21 in contact with the shoe sole body 3 to be molded. Thus, the adhesion between the shoe sole main body 3 and the vulcanized rubber grounding bottom 1 is ensured.
[0008]
【The invention's effect】
As described above, the vulcanized rubber ground sole 1 which is formed by this invention, without the need to apply the adhesive, is bonded integrally with the sole body 3 when the shoe sole body injection molding, the sole body 3 A shoe sole having a vulcanized rubber grounding bottom 1 excellent in adhesiveness can be obtained at low cost.
[0009]
【Example】
A flat yarn woven fabric made of polypropylene having a melting point of 160 ° C. and having a melting point of 160 ° C. is used as the core fabric 23, and a 450 g / m ² polyester fiber web is overlapped on the upper and lower sides thereof at a melting point of 260 ° C. A non-woven fabric having a thickness of 2 mm, in which upper and lower fiber fabrics 21 and 22 made of upper and lower fiber webs are entangled with a core layer 23 by a punch, is cut into a grounded bottom shape to prepare and prepare an upper fabric 2. Is laminated on the upper surface of the grounded bottom molding material 11 made of unvulcanized rubber fabric at the time of grounded bottom molding, and this is heated and pressed at 160 ° C. and a press gauge pressure of 100 kgf / cm ² for 7 minutes by a conventional method. A rubber ground bottom 1 was molded. The vulcanized rubber grounding bottom 1 molded in this way is set on the bottom of a shoe sole molding die at the time of polyurethane shoe sole main body injection molding without applying an adhesive, and liquid is put into the shoe sole molding cavity by a conventional method. A shoe sole body molding material made of polyurethane was injected and molded to form a urethane foam shoe sole body 3, and a vulcanized rubber grounding bottom 1 was insert-molded integrally with the stepping part and the buttock grounding surface. The shoe sole formed in this way does not hinder the flexibility of the shoe sole. A shoe sole excellent in adhesiveness between the vulcanized rubber grounding bottom 1 and the shoe sole body 3 was obtained at a low cost without causing the upper cloth 2 to delaminate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing a state of forming a grounded bottom.
FIG. 2 is a cross-sectional view of a main part showing a molded state of a shoe sole.
[Explanation of symbols]
1. 10. Vulcanized rubber ground bottom, . . 1. Ground bottom molding material, 21. Upholstery cloth . . 21. upper fiber cloth, . . Lower fiber fabric, 23. . . 2. core layer; The sole body

Claims

Core layer with a melting point is laminated an upper fabric 21 and the lower fabric 22 vertically to the melting point is above 200 ° C. of the core layer 23 made of heat-adhesive synthetic resins or fibers in the range of vulcanization temperature ± 20 ° C. 23 is made of an olefin-based flat yarn cloth, and the upper adhesive cloth 2 entangled with the fiber web constituting the upper and lower fibers 22.23 is arranged on the upper surface of the ground bottom molding material 11 made of unvulcanized rubber. This is heated and pressed at 140 to 180 ° C. to form the vulcanized rubber grounding bottom 1, and a lower-layer fiber cloth 22 is laminated below the upper cloth 2 in contact with a part of the grounding bottom molding material 11. Vulcanized rubber for injection-molded shoe soles, wherein the core layer 23 is softened or melted and adhered to the upper and lower fiber fabrics 21.22 laminated on the upper and lower sides thereof. Molding method for grounding bottom.