WO2003042301A1

WO2003042301A1 - Resin composition, process for its production and use thereof

Info

Publication number: WO2003042301A1
Application number: PCT/JP2002/011379
Authority: WO
Inventors: Kazuya Kotani
Original assignee: Daicel Chemical Industries, Ltd.
Priority date: 2001-11-12
Filing date: 2002-10-31
Publication date: 2003-05-22
Also published as: BR0206430A; JP2003147181A; TW593536B

Abstract

A resin composition comprising 25 to 95 wt% of polycaprolactone (A) and 5 to 75 wt% of polyvinyl alcohol (B) (with the proviso that the sum total of (A) and (B) is 100 wt%), characterized in that the polyvinyl alcohol (B) is dispersed in the matrix of the polycaprolactone (A) in the form of particles having diameters of 2 mm or below; a process for the production of the resin composition by kneading a mixture of polycaprolactone (A) and polyvinyl alcohol (B) at a temperature which is the melting temperature of the polycaprolactone (A) or above but below the melting temperature of the polyvinyl alcohol (B); and cores for footwear, produced by molding the resin composition. The invention enables one-step production of the above resin composition and can give cores for footwear which can be bonded by heat reactivation without any organic solvent.

Description

Description Resin composition, method for producing the same and use thereof

The present invention relates to a resin composition comprising a specific resin. More specifically, a resin composition composed of polycaprolactone and polypinyl alcohol, used in the manufacture of various types of footwear, especially men's shoes, women's shoes, children's shoes, boots, sports shoes, casual shoes, sandals, slippers, etc. The present invention relates to a resin composition suitable for a core material for footwear such as a leading core and a lunar core. Background art

Conventionally, shoe cores have been used to give shape retention to the tip and heel of shoes, and woven or non-woven fabric impregnated with thermoplastic resin is used for the shoe tip and heel. It is used by being adhered to the inside.

Conventional shoe cores can be classified into several types depending on the method of bonding to the shoe. In the first type, the core material is reactivated with a solvent (in the present invention, activation means making it attachable) and adheres to a predetermined part of the shoe. Woven fabrics and nonwoven fabrics are impregnated with a thermoplastic resin emulsion such as emulsion, styrene-acrylic copolymer emulsion or the like, and dried and solidified to form a sheet. The second type is a method of bonding a core material to a shoe with an adhesive, for example, a method of bonding a sheet having a composition used in the first type with a natural rubber latex type adhesive. The third type is a method of bonding a core material to shoes by thermal reactivation. For example, an ethylene / vinyl acetate copolymer hot melt adhesive or poly A sheet composed of a thermoplastic resin composition mainly composed of prolactone and a woven fabric / nonwoven fabric is subjected to thermal reactivation. To be bonded to shoes. For example, Japanese Unexamined Patent Publication (Kokai) No. 56-148301 discloses a thermoplastic thermoplastic resin for shoes mainly composed of a polyforced prolactone having a weight average molecular weight of from 10,000 to 200,000. A core material is described.

Each of the above types of shoe core material has a problem to be solved. First, the first type of core material and its bonding method are low in cost and have good workability at the time of bonding. However, since an organic solvent is used at the time of bonding, there is a problem in the working environment in the shoemaking process. There is a danger of fire and fire, so it does not match the demands of the times. In the second type of bonding method, the core material is bonded to the shoes using an adhesive, and the greatest difficulty is that the workability is poor because the number of work steps increases. The third type of core material and bonding method has an advantage that the core material can be bonded to the shoe by thermal reactivation, so that an organic solvent is not required and workability is excellent. However, the core material used in this type is manufactured by impregnating a woven fabric or the like with a thermoplastic resin such as styrene emulsion and drying and solidifying it. It requires a step of coating the agent, which has the disadvantage of increasing manufacturing costs. Furthermore, since the hot melt adhesive is applied to the woven or non-woven fabric, the surface that is not coated with the hot melt adhesive is used as the adhesive surface when the cut surface is skived (sharpened). It has the disadvantage of appearing. In addition, the core material consisting of a thermoplastic resin composition mainly composed of polycaprolactone and a woven fabric / nonwoven fabric uses polyvinyl chloride resin as a filler or reinforcing agent in the thermoplastic resin composition. However, they have a dioxin problem that occurs when incinerating unnecessary shoes. Disclosure of the invention

An object of the present invention is to provide a core material for footwear (hereinafter simply referred to as a core material) that does not require an organic solvent at the time of bonding and can be bonded by heat reactivation, and can be manufactured in one step. A novel resin composition is provided. In addition, even if a skiving process is performed, the entire bonding surface of the core material can be bonded by heat reactivation without applying a new bonding agent to that surface. It is an object of the present invention to provide a resin composition which becomes a core material for footwear, and which gives a footwear core material free from generation of dioxin due to the composition of a molded product when incinerated at the stage of use. The present inventors can solve such a problem that a resin composition in which polyvinyl alcohol having a specific particle size is dispersed in the form of powder in a matrix of polyprolactone and a core material molded therefrom. This led to the completion of the present invention.

That is, the first aspect of the present invention is that 25% to 95% by weight of polyproprolactone (A) and 5% to 75% by weight of polyvinyl alcohol (B) (the total of (A) and (B) is 100% by weight). %), Wherein the polyvinyl alcohol (B) is dispersed in a matrix of the polyprolactone (A) in the form of powder having a particle size of 2 mm or less.

A second aspect of the present invention provides the first resin composition of the present invention, in which the number average molecular weight of the polyfunctional prolactone (A) is from 10,000 to 150,000.

The third aspect of the present invention is a polyproprolactone (A) of 25 to 95% by weight and a granular polyvinyl alcohol (B) having a particle size of 2 mm or less 5 to 75% by weight ((A) and (B) ) Is kneaded at a temperature equal to or higher than the melting point of the polycaprolactone (A) and lower than the melting point of the polyvinyl alcohol (B). A method for producing the resin composition according to 1 or 2 is provided.

A fourth aspect of the present invention provides a method for producing the third resin composition of the present invention, wherein the kneading temperature is from 80 to 200.

A fifth aspect of the present invention provides a core material for footwear obtained by molding the resin composition according to the first or second aspect of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described.

The polyfunctional prolactone used in the present invention (hereinafter abbreviated as PCL) (A) 25-95% by weight, preferably 30-70% by weight, based on a total of 100% by weight of polyvinyl alcohol (hereinafter abbreviated as PVA) (B) in the resin composition of Is done. If the proportion of PCL (A) is less than 25% by weight, if it is used as a molded body for a core material, sufficient adhesiveness due to thermal reactivation cannot be obtained. On the other hand, when the proportion of PCL (A) is more than 95% by weight, the shape retention as a core material is not satisfied, and further, it is not preferable from the viewpoint of raw material cost.

The number average molecular weight of the PCL (A) used in the resin composition of the present invention is preferably 10,000 to 150,000 from the viewpoint of bending resistance when the resin composition of the present invention is used as a core material. 000, and more preferably in the range of 30,000 to 130,000. If the number average molecular weight of PCL (A) is more than 150,000, handling operability and the like when manufacturing a molded product for a core material deteriorate. PVA (B) constituting the resin composition of the present invention includes PVA which is generally used for synthetic fibers, powdery and granular PVA which is used for films (all are completely saponified polyvinyl acetate), partially saponified products, It may be a specially modified partially saponified product or a mixture thereof. In the resin composition of the present invention, PVA (B) is dispersed in the matrix of PCL (A) in the form of powder having a particle size of 2 mm or less, and a total of 100% by weight of the PCL (A) in the resin composition. % Must be contained in the range of 5 to 75% by weight.

Compared with other polymer particles, such as polyvinyl chloride and polypropylene particles, PVA particles have a moderate affinity for the PCL of the matrix due to the molecular structure of PVA itself. Particles existing on the surface of the core material obtained from the resin composition hardly fall off. Furthermore, it is easily dispersed in the matrix of PCL by kneading, and once dispersed, no re-aggregation of particles is observed.

Here, the granular form refers to a state as it is produced in the form of a granular form, or a granular form or a granular form produced by subsequent operations such as pulverization, crushing, granulation, drying, sieving, and the like. The shape does not matter. Needless to say, the particle may have a shape in which at least a part of the surface of the particle is melted and rounded, and a spherical shape or an approximate shape thereof. Also, "dispersed in the matrix of PCL" means that when the obtained resin composition is formed into a thin sheet and visually observed with transmitted light, substantially no uneven distribution of particles is observed. means.

When the PVA (B) has a particle size of 2 mm or less and the powdery shape is not maintained, the effect of the present invention is not exhibited. That is, when the PCL (A) and the powdered PVA (B) are mixed by heating at a temperature higher than the melting point of the PVA, the PVA (B) is melted and melt-blended with the PCL (A) to form a uniform melt. Form. In this case, even when cooled, no particulate PVA is visually observed in the composition. The core material obtained by molding such a resin composition has reduced adhesive strength when bonded to a predetermined part of the shoe by thermal reactivation. In addition, when powdered PVA (B) is unevenly distributed in PCL while maintaining its shape, in many cases, shape retention and mechanical strength as a core material are not satisfied. Even those variations are large. Furthermore, the heat reactivation reduces the bonding strength when bonding to a predetermined part of the shoe. When the proportion of PVA (B) contained in the resin composition is less than 5% by weight, the shape retention and mechanical strength of the core material molded product are not satisfied. On the other hand, when the proportion of PVA (B) is more than 75% by weight, the adhesive strength when the material obtained by molding the resin composition is adhered to a predetermined part of the shoe by thermal reactivation is not satisfied. The particle size of the dispersed PVA (B) particles is 2 mm or less, preferably 1.5 to 0.1 mm. When the particle size of PVA (B) is larger than 2 mm, the obtained core material is used because the PVA particles protrude from the bonding surface of the core material, or the PVA particles easily come off from the core material surface. The heat reactivation reduces the adhesive strength when bonding to a predetermined part of the shoe. Various additives may be added to the resin composition of the present invention as needed. these The additives are not particularly limited. For example, in order to adjust the open time when the molded body as a core material is bonded to a predetermined part of the shoe by thermal reactivation, a resin and a derivative thereof, a terpene are used. Small amounts of compounds, hydrocarbon compounds, paraffin wax, and low molecular weight polyethylene wax may be added. In addition, an antioxidant (an antioxidant) may be added during hot-melt mixing of the resin composition, at the time of hot-melt processing of a core material obtained by molding, or at the time of reactivating the core material by heat. A small amount may be added to improve thermal stability. In addition, for the purpose of improving the core material's cold resistance, flexibility, impact resistance, surface altitude, etc., olefin resin, styrene resin, urethane resin and ester copolymer, glass fiber, Filaments such as glass beads, calcium carbonate, barium sulfate, titanium oxide, clay, and curk may be arbitrarily added as long as the effects of the present invention are not impaired. In the production of the resin composition of the present invention, it is not necessary to use a particularly limited method and apparatus. In general, PCL pellets, powdery PVA, and optionally additives are mixed by heating and kneading. , Compound. For example, the compound can be made by a single-screw or twin-screw extruder. At this time, the compound is heated and kneaded at a temperature lower than the melting point (softening point) of PVA (B) and higher than the melting point of PCL so as not to melt PVA (B). It is necessary to set the temperature, preferably in the range of 80 to 200. Prior to heating and kneading, following the manufacture of once taking out a Peretsuto like, or a resin composition The resin composition of the pre-dry-blended in advance also good _c present invention the constituent raw materials of the resin composition of the present invention, the core material It is put into a molding sheet molding machine or injection molding machine, and a molded body as a core material can be obtained at a temperature lower than the melting point of PVA (B). Example

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. (Examples 1 to 10, Comparative Examples 1 to 4)

Resin compositions having the compositions shown in Table 1 (parts by weight are shown except for the kneading temperature) were produced. After pre-driving each of the constituent materials at a predetermined ratio, these resin compositions were put into a Toyo Seiki Labo Plast Mill (mixer unit R-60) at a time, and the kneading temperature and kneading shown in Table 1 were performed. The composition was kneaded under a kneading condition of a rotation speed of 5 Or.pm and a kneading time of 3 minutes to obtain a composition. Except for Comparative Example 1, the kneading temperature was set to a temperature (at 100) lower than the melting point of the PVA used.

Each composition was prepared (Examples 1 to 10 and Comparative Examples 1 to 4) in the flop-less molding machine heated to 1 10, the primary pressure 1 0 kg cm ² for 3 minutes, the secondary pressure l OO kgZ cm ² A sheet having a thickness of 1.2 mm was formed by applying pressure for 2 minutes. These sheets were evaluated to confirm the characteristics as a core material molded body, and the results are shown in Table 2.

The molded article of Comparative Example 2 was judged to have no bending resistance and toughness required as a molded article for a core material because the sheet was broken when it was bent because of its high brittleness when molded into a sheet. Each evaluation was not performed. Also, in the composition of Comparative Example 1, the kneading temperature at the time of manufacturing the composition was higher than the melting point of the PVA (at 217), so that the PVA was melted and dissolved in the PCL, and the particles of the PVA were melted. The shape was not maintained, but in the other Examples and Comparative Examples, the particle shape of PVA was maintained. Further, in the composition in which the particle shape of PVA was maintained, visual observation using transmitted light of the sheet showed that the particles were uniformly dispersed without uneven distribution or agglomeration. The methods for measuring physical properties are described below.

PCL number average molecular weight: This is the molecular weight calculated from polystyrene by GPC measurement. GPC uses Shode X GPC KF-6, KF-804, KF-8025, KF-801 manufactured by Showa Denko KK as a column, and RID-6A manufactured by Shimadzu Corporation as a detector. The eluent was tetrahydrofuran, and the measurement was performed at a column temperature of 50 and a flow rate of 1.0 ml 1 Zmin. Adhesion: The sheets manufactured in Examples 1 to 10 and Comparative Examples 1 and 3 to 4 were prepared to have a size of 7 cm long × 2.5 cm wide × 1.2 mm thick. After placing these strips on a stainless steel plate placed horizontally in a dryer at 150 for 40 seconds, immediately take them out of the dryer and let them stand naturally for 30 seconds. These strip sheets were placed on the polyester woven cloth that had been cut, and cold-pressed at a pressure of 1 kg / cm ² for 10 seconds with a press adjusted at 30. The cloth was glued. At that time, a strip of 2 cm in length was used as a grip for the T-peel test so that aluminum foil was sandwiched between the strip and the woven fabric so as not to adhere. The adhesion was evaluated by a T-type peel test at a peel speed of 10 Omm / min using Tensilon manufactured by ORI ENTEC, and the average peel strength was evaluated.

Flex resistance: The sheets of Examples 1 to 10 and Comparative Examples 1 and 3 to 4 were prepared to have a size of 14 cm in length × 3.0 to 111 in width and a thickness of 1.2 mm. These strip sheets were set in a bending resistance tester so that the longitudinal direction of the strip sheets were bent, and the strip sheets were repeatedly bent with a stroke of 4.7 cm for a width of 10.5 cm. The repetitive bending speed at this time was set to 300 minutes (one reciprocation: one) Z minutes. The evaluation was performed based on the number of times of bending when the strip sheet was broken.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4

^{PCL - A * 1/8 /1.4} 40 40 85 82.4 37.5 66.7 O0.7 /1.4 71.4 47.9

PCL-B * ² 71.4 25.0

PCL-C * ³ 71.4

P VA-A * ⁴ 22 28.6 60 60 15 17.6 37.5 33.3 33.3 28.6 28.6 52.1

P VA-B * ⁵ 28.6

P VA-C * ⁶ 28.6

ST copolymer * ⁷ 5.6 10.0 26.7 11.8 10.0 8.8 10.0 10.0 10.0 56.3

OL copolymer A ⁸ 13.3

0-based copolymer 8 "13.3

Hydrocarbon compounds ¹¹¹ n 5.6 4.3 6.7 5.9 4.3 3.8 4.0 4.0 4.3 4.3 4.3 10.4 Glass fiber filler ' ^{1 1} 28.6 28.6 12.5 16.0 16.0 28.6 28.6 28.6 41.7 Kneading temperature / 100 100 100 100 100 100 100 100 100 100 230 100 100 100

PCL—A * ¹ : Polycaprolactone (manufactured by Daicel Chemical Industries, Ltd., PCLH5, number average molecule 52000, melting point 60)

PCL—B * ² : Polyprolactone (PCLH7, Daicel Chemical Co., Ltd., number average molecule 132000, melting point 60 * C)

PCL-C ^'3: Poly force caprolactone (Daicel Chemical Co., Ltd., PCLH1P, number average molecular 9600, with melting point 60)

PVA—A * ⁴ : Polyvinyl alcohol powder (Kuraray Co., Ltd., PVA-117, melting point 217 ^, particle size 2 mm or less)

PV A— B * ⁵ · .Polyvinyl alcohol (Kuraray Co., Ltd., PVA-117s, melting point 2Πΐ, particle size 0.4 mm or less)

PVA-C * ⁶ : Powdered polyvinyl alcohol (Kuraray Co., Ltd., 'H-Hall' PVA-117, melting point: 217, which can be classified from those with a particle size of more than 2 mm.) Polymer ' ⁷ : JSR Corporation, styrene copolymer, JSRTR2000

OL copolymer A ^'8: Nippon Petrochemicals Co., Orefin copolymer, Nisseki Rexpearl RB3240

OL copolymer B * ⁹ : Olefin copolymer, Evaflex EV150, manufactured by DuPont-Mitsui Polychemicals, Inc.

Hydrocarbon compounds' ^1D : Nippon Petrochemical Co., Ltd., Nisseki Hizol SAS H

Glass fiber filler ¹ : T-123, manufactured by Nippon Electric Insulators, Ltd.

Table 2

Industrial applicability

ADVANTAGE OF THE INVENTION According to this invention, since the adhesion | attachment by heat reactivation is good and the physical property required as a core material, for example, bending resistance is good and since a halogen type compound is not used, generation | occurrence | production of dioxin at the time of combustion The present invention can provide a footwear core material having no problem, and a resin composition for providing the same.

Claims

The scope of the claims

1. 25% to 95% by weight of polycaprolactone (A) and 5 to 75% by weight of polyvinyl alcohol (B) (total of (A) and (B) is 100% by weight). ) Is dispersed as a powder having a particle size of 2 mm or less in a matrix of the polyprolactone (A).

2. The resin composition according to claim 1, wherein the number average molecular weight of the polyfunctional prolactone (A) is 10,000 to: 150,000.

3. 25% to 95% by weight of polycaprolactone (A) and 5 to 75% by weight of powdery polyvinyl alcohol (B) with a particle size of 2 mm or less (the total of (A) and (B) is 100% by weight). 3. The method for producing a resin composition according to claim 1, wherein the mixture is kneaded at a temperature equal to or higher than the melting point of the polycaprolactone (A) and lower than the melting point of the polyvinyl alcohol (B).

4. footwear core material kneading temperature is obtained by molding the resin composition according to the manufacturing method _c 5. Claim 1 or 2 of the resin composition according to the is claim 3 80-200.