US3624191A - Footwear - Google Patents
Footwear Download PDFInfo
- Publication number
- US3624191A US3624191A US793559*A US3624191DA US3624191A US 3624191 A US3624191 A US 3624191A US 3624191D A US3624191D A US 3624191DA US 3624191 A US3624191 A US 3624191A
- Authority
- US
- United States
- Prior art keywords
- insole
- footwear
- resin
- shoe
- percent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 claims description 9
- 229920005989 resin Polymers 0.000 abstract description 25
- 239000011347 resin Substances 0.000 abstract description 25
- 239000000203 mixture Substances 0.000 abstract description 13
- 239000004698 Polyethylene Substances 0.000 abstract description 10
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 abstract description 10
- -1 polyethylene Polymers 0.000 abstract description 10
- 229920000573 polyethylene Polymers 0.000 abstract description 10
- 239000000853 adhesive Substances 0.000 abstract description 8
- 230000001070 adhesive effect Effects 0.000 abstract description 8
- 239000005038 ethylene vinyl acetate Substances 0.000 abstract description 8
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 abstract description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 239000004604 Blowing Agent Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 9
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 229920001577 copolymer Polymers 0.000 description 5
- 239000002667 nucleating agent Substances 0.000 description 5
- 229920001084 poly(chloroprene) Polymers 0.000 description 5
- 239000010985 leather Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 4
- 239000004831 Hot glue Substances 0.000 description 3
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 3
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 2
- 239000001273 butane Substances 0.000 description 2
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 description 2
- 239000001639 calcium acetate Substances 0.000 description 2
- 235000011092 calcium acetate Nutrition 0.000 description 2
- 229960005147 calcium acetate Drugs 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000011094 fiberboard Substances 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- BCZXFFBUYPCTSJ-UHFFFAOYSA-L Calcium propionate Chemical compound [Ca+2].CCC([O-])=O.CCC([O-])=O BCZXFFBUYPCTSJ-UHFFFAOYSA-L 0.000 description 1
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- NAMBGWYANBMQBJ-UHFFFAOYSA-N N(=O)NCCCCCNN=O Chemical compound N(=O)NCCCCCNN=O NAMBGWYANBMQBJ-UHFFFAOYSA-N 0.000 description 1
- 229920012485 Plasticized Polyvinyl chloride Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 229920001131 Pulp (paper) Polymers 0.000 description 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 150000001350 alkyl halides Chemical class 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 235000010338 boric acid Nutrition 0.000 description 1
- 239000001058 brown pigment Substances 0.000 description 1
- 239000004301 calcium benzoate Substances 0.000 description 1
- 235000010237 calcium benzoate Nutrition 0.000 description 1
- 239000004330 calcium propionate Substances 0.000 description 1
- 235000010331 calcium propionate Nutrition 0.000 description 1
- HZQXCUSDXIKLGS-UHFFFAOYSA-L calcium;dibenzoate;trihydrate Chemical compound O.O.O.[Ca+2].[O-]C(=O)C1=CC=CC=C1.[O-]C(=O)C1=CC=CC=C1 HZQXCUSDXIKLGS-UHFFFAOYSA-L 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000002666 chemical blowing agent Substances 0.000 description 1
- NEHMKBQYUWJMIP-NJFSPNSNSA-N chloro(114C)methane Chemical compound [14CH3]Cl NEHMKBQYUWJMIP-NJFSPNSNSA-N 0.000 description 1
- 229960001701 chloroform Drugs 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 229920006026 co-polymeric resin Polymers 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229910001872 inorganic gas Inorganic materials 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 150000002897 organic nitrogen compounds Chemical class 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000011975 tartaric acid Substances 0.000 description 1
- 235000002906 tartaric acid Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
-
- A—HUMAN NECESSITIES
- A43—FOOTWEAR
- A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
- A43B13/00—Soles; Sole-and-heel integral units
- A43B13/38—Built-in insoles joined to uppers during the manufacturing process, e.g. structural insoles; Insoles glued to shoes during the manufacturing process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/10—Surface shaping of articles, e.g. embossing; Apparatus therefor by electric discharge treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/04—Polymers of ethylene
- B29K2023/06—PE, i.e. polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/48—Wearing apparel
- B29L2031/50—Footwear, e.g. shoes or parts thereof
- B29L2031/507—Insoles
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/04—Homopolymers or copolymers of ethene
Definitions
- an insole comprising an extruded foamed resin sheet having a substantially uniform thickness of 0.04-0.2 inch, a substantially closed cell structure, and a density of 17-40 pound per cubic foot from a resin which is an ethylene-vinyl acetate copolymer or a blend thereof with polyethylene and which contains 2-l 7 percent by weight of polymerized vinyl acetate, (2) bonding the insole to a relatively rigid heel board to form an assembly, an (3) bonding the other components of a shoe or the like to said assembly to form an article of footwear.
- the foamed sheet has a substantially closed cell structure, i.e., the majority, normally at least 90percent, of the cells are closed.
- the majority, and more preferably at least 75 percent, of the cells have a diameter of 0.0040.04 inch e.g., 0.0 l-0.03 inch.
- the blowing agent is sometimes employed in conjunction with a nucleating agent, which assists in the formation of a large number of fine cells.
- a nucleating agent can be employed, including finely divided inert solids such as silica or alumina (optionally in conjunction with zinc stearate), or small quantities of a substance that decomposes at the extrusion temperature to give a gas can be used.
- An example of the latter class of nucleating agents is sodium bicarbonate, optionally in conjunction with a weak acid such as tartaric or citric acid. Boric acid, calcium acetate, calcium propionate, and calcium benzoate are also excellent nucleating agents.
- a small proportion of the nucleating agent e.g., up to 5 percent by weight of the resin, is usually effective.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
Abstract
Footwear, such as a boot or shoe, having an insole comprising an extruded foamed resin sheet wherein the resin is an ethylenevinyl acetate copolymer or a blend thereof with polyethylene and has a polymerized vinyl acetate content of 2-17 percent by weight. The insole has a substantially uniform thickness, a substantially closed cell structure, and a density of 17-40 pounds per cubic foot. Preferably, the insole is treated with an electric discharge prior to being bonded to the other components of the article of footwear. The insole can be bonded to these other components by any suitable means, preferably by the use of an adhesive.
Description
United States Patent lnventor Donald Weight Chaliont Saint Giles, England Appl. No. 793,559 Filed Jan. 23, 1969 Patented Nov. 30, 1971 Assignee Monsanto Chemicals Limited London, England Priority Feb. 1, 1968 Great Britain 5232/68 FOOTWEAR 3 Claims, No Drawings US. Cl 264/45, 18/D1G. 13,12/146 Int. Cl 829d 27/00 Field of Search 264/45, 53, 47; 18/DIG. 13; 12/146, 147
References Cited UNITED STATES PATENTS 8/1951 Simorda l8/DIG. 13
3,080,589 3/1963 Midgley 12/146 3,348,251 [0/1967 Appleton et al. 12/147 3,379,802 4/1968 Raley et a1. 264/53 ABSTRACT: Footwear, such as a boot or shoe, having an insole comprising an extruded foamed resin sheet wherein the resin is an ethylene-vinyl acetate copolymer or a blend thereof with polyethylene and has a polymerized vinyl acetate content of 2-17 percent by weight. The insole has a substantially uniform thickness, a substantially closed cell structure, and a density of 17-40 pounds per cubic foot. Preferably, the insole is treated with an electric discharge prior to being bonded to the other components of the article of footwear. The insole can be bonded to these other components by any suitable means, preferably by the use of an adhesive.
FOOTWEAR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to footwear and more particularly relates to a novel insole comprising an extruded foamed resin sheet and to an article of outer footwear, such as a boot or shoe, having such an insole.
2. Description of the Prior Art In the construction of outer footwear such as boots and shoes, the upper is normally fastened to an assembly comprising an insole and a heel board while the assembly is held on a last, a sole and heel are then fastened to the underside of the assembly, and the parts of the insole and heel board visible within the shoe are finally covered by a lining or sock. The heel board is usually made of a relatively rigid material such as fiberboard, but the insole needs to be more flexible. The nature of the insole is indeed of extreme importance in determining the comfort and life expectancy of the shoe as a whole, since it serves to hold the upper to the sole and also to cushion the foot of the wearer. As has been mentioned, the insole needs to be flexible in the interests of comfort, but another important requirement that generally militates against flexibility is the need for good recovery," i.e., ability of the shoe to regain its original shape after being subjected to deformation in use. Repeated flexure and impact when the shoe is in use result in deformation of the shoe as a whole, and, unless a shoe has the ability to recover overnight from the effects of being worn for a day, it will give only a few months wear before generally deteriorating, becoming ill fitting, uncomfortable, and unattractive in appearance.
Hitherto, it has been usual to employ for the production of insoles such materials as cardboard, paper pulp, leather pulp, leather, and similar materials, usually treated with a resin in order to afford some resistance to moisture. However, such materials suffer from the very real disadvantage that they are not as flexible as is desirable, and, even when treated with a resin, they absorb moisture either from outside the shoe or from a perspiring foot. When moist, they are readily deformed and have a tendency to disintegrate or delaminate, thus admitting water through the edge of the insole, which in turn leads to very rapid disintegration of the structure of the shoe as a whole. Perspiration can also cause some of these materials to rot. Some synthetic materials have been tested as insoles but have been found to be defective either because of insuffici'ent flexibility or because of a tendency to spread," i.e., stretch so that the necessary shape retention is not obtained. It can therefore be seen that the choice of an insole material is not simple matter and that the materials that have hitherto been proposed fall well short of the ideal.
SUMMARY OF THE INVENTION An object of the invention is to provide a novel insole having good flexibility, resistance to moisture, and recovery.
Another object is to provide an article of footwear having such an insole.
These and other objects are attained by (l) forming an insole comprising an extruded foamed resin sheet having a substantially uniform thickness of 0.04-0.2 inch, a substantially closed cell structure, and a density of 17-40 pound per cubic foot from a resin which is an ethylene-vinyl acetate copolymer or a blend thereof with polyethylene and which contains 2-l 7 percent by weight of polymerized vinyl acetate, (2) bonding the insole to a relatively rigid heel board to form an assembly, an (3) bonding the other components of a shoe or the like to said assembly to form an article of footwear.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples are given to illustrate the invention and are not intended as a limitation thereof. Unless otherwise specified, quantities mentioned are quantities by weight.
EXAMPLE I Dry blend 98parts of an ethylene-vinyl acetate (88:12) copolymer resin in granular form with 2parts of anhydrous calcium acetate, and feed the resulting mixture into the hopper of a screw extruder having a barrel with a nominal diameter of 1.5 inches. Inject nitrogen under pressure into the molten mixture in the extruder barrel, and extrude the resulting foamable composition at a temperature of C. into the atmosphere through a slit die having a length of 6inches and a width of 0.025 inch. The product is a soft foam strip having a thickness of 0.08 inch, a density of 24 pounds per cubic foot, and a fine closed cell structure.
Subject both sides of the sheet to the action of an alternating electric discharge of 10,000 volts and 3 kilocycles per second by passing the sheet between the two electrodes spaced 0.l5 inch apart, each part of the sheet being exposed to the discharged for 0.I second. Cut the sheet into pieces in the shape of insoles suitable for ladies casual shoes, and adhere each insole to a heel board made of a cellulose fiberboard known as shank boar by means of a neoprene adhesive at 70 C. for 5 seconds under pressure. Then adhere the resulting assembly to a leather upper by means of a neoprene adhesive applied at 70 C. for 5 seconds, and finally attach a rubber composition sole and heel to the assembly, also by a neoprene adhesive.
The resulting shoe has a very flexible and comfortable sole. The insole survives extended wearer trials without failure, whereas a pulped leather insole in an otherwise identically constructed shoe disintegrates after only a few months. The resistance to moisture of the insole of the invention is excellent. The recovery ability of the shoe of the invention is infinitely superior to that of the control shoe, the latter being misshapen and ill-fitting after only 3 months whereas the shoe of the invention retains its good shape and fit after 12 months of use.
Trials of other women's and children's shoes according to the invention show no case of failure due to insole cracking, the trials always being ended by failure of a different component of the shoe. EXAMPLE I] Repeat Example I except for substituting an ethylene-vinyl acetate (96:4) copolymer for the ethylene-vinyl acetate (88: l 2) copolymer. The resulting shoe is similarly flexible and comfortable and is just as successful in passing wearer trials. The insole has the additional advantage of reduced sensitivity to the effects of heat during application of the neoprene adhesive, thus permitting the use of slightly more severe bonding conditions if required.
The resin used in the practice of the invention preferably contains from 3 or 7 to 15 percent by weight of polymerized vinyl acetate, e.g., 3-5 percent by weight. As demonstrated in the Examples, excellent results are obtained employing resins containing, respectively, about 4 percent and about 12 percent by weight of vinyl acetate. Preferably, the resin is in ethylene-vinyl acetate copolymer, but it can be a blend of polyethylene with such a copolymer. When it is a blend, the proportion of vinyl acetate in the copolymer can, of course, be greater than 17 percent by weight, e.g., up to 30 percent or even 45 percent weight, sufficient polyethylene being blended with the copolymer to reduce the vinyl acetate content of the resin as a whole to a value within the required range. The polyethylene can be of the low-pressure type made using a chromium oxide or organometallic catalyst system, but it is preferably a high-pressure polyethylene, e.g., a polyethylene having a density of 0.90-0.94 grams per cc. Ethylene and vinyl acetate are usually the only monomers polymerized into the resin, but a small proportion not exceeding 3 or 5 percent by weight of the total, of a third monomer such as propylene or methyl methacrylate can be polymerized into the resin if desired.
The sheet has a substantially unifonn thickness, i.e., the thickness does not vary by more than 15 percent. Preferably, any thickness variation is not greater than 5 percent. The type of footwear being made determines the choice of insole thickness ordinarily, thinner insoles usually being needed for children's and ladies shoes than for men's boots or shoes. Preferably, the thickness is from 0.05 to 0.1 or 0.15 inch; very often 0.06-0.085 inch is particularly suitable.
The foamed sheet has a substantially closed cell structure, i.e., the majority, normally at least 90percent, of the cells are closed. Preferably the majority, and more preferably at least 75 percent, of the cells have a diameter of 0.0040.04 inch e.g., 0.0 l-0.03 inch.
The e.g., of the sheet is very often 20-40 pounds per cubic foot, preferably 22-30 pounds per cubic foot; and a density at the lower end of this range; e.g., about 24 pounds per cubic foot, is usually most suitable. The sheet may have a nonfoamed skin on each side, but this is not usually thicker than about 0.002 inch.
The foamed sheet is an extruded one and is normally made by extruding a foamable mixture of the resin and a suitable blowing agent under pressure through a die into a zone of lower pressure (usually the atmosphere) so that the expansion of the blowing agent and foaming of the resin take place. Usually a slit die is used but it is also possible to employ an annular die to extrude a tube of foamed resin that is later slit longitudinally and opened out into a flat sheet. When a slit die is used, it can have a flared outlet if desired, and a pair of rollers can be placed in front of it so that the extruding sheet passes between them; such rollers assist in the production of a smooth flat sheet free of thickness variations and corrugatrons.
As indicated above, any suitable blowing agent can be used but the preferred blowing agents are those which are gases or vapors under normally atmospheric conditions. Volatile I liquids can also be used. in may cases, the blowing agent is one that is normally gaseous but which, while under pressure before extrusion, will be present in solution in the molten or semimolten resin. Exemplary of volatile blowing agents that can be used are lower aliphatic hydrocarbons such as ethane, propane, butane, pentane, etc., lower alkyl halides such as methyl chloride, trichloromethane, l ,2- dichlorotetrafluorethane, etc.; and inorganic gases such as carbon dioxide or nitrogen. Nitrogen and the lower aliphatic hydrocarbons, especially butane or isobutylene, are preferred; and a mixture of nitrogen and a lower aliphatic hydrocarbon is often particularly useful. The blowing agent can also be a chemical blowing agent, e.g., a bicarbonate such as sodium bicarbonate or ammonium bicarbonate, or an organic nitrogen compound that yields nitrogen on heating, such as dinitrosopentamethylenediamine or barium azodicarboxylate. In the case of a liquid or readily liquiflable blowing agent, 13-30 percent, especially 7-20 percent, based on the weight of resin, is often a suitable proportion. When the blowing agent is permanent gas, it is more convenient to consider relative volumes at standard temperature and pressure. For example, the use of 0.5- parts, preferably l-2 parts, by volume of nitrogen at S.T.P. in conjunction with 1 part by volume of polyethylene give excellent results. The use of amounts of blowing agent at a lower end of the above ranges often results in the production of a thicker sheet.
The blowing agent is sometimes employed in conjunction with a nucleating agent, which assists in the formation of a large number of fine cells. A wide range of nucleating agents can be employed, including finely divided inert solids such as silica or alumina (optionally in conjunction with zinc stearate), or small quantities of a substance that decomposes at the extrusion temperature to give a gas can be used. An example of the latter class of nucleating agents is sodium bicarbonate, optionally in conjunction with a weak acid such as tartaric or citric acid. Boric acid, calcium acetate, calcium propionate, and calcium benzoate are also excellent nucleating agents. A small proportion of the nucleating agent, e.g., up to 5 percent by weight of the resin, is usually effective.
The resin can also contain such additives as coloring agents,
antioxidants, stabilizers, lubricants etc., if desired. For example, It IS often desirable to color the resrn when it IS to form part of asandal, the construction of which renders the edge of the insole visible as the welt. A clay or other brown pigment is very often suitable for this purpose.
According to a preferred feature of the invention, the sheet is subjected to the action of an electric discharge. This has been found not only to improve the adhesion of hot melt and other adhesives to the insole, but also surprisingly to reduce undesirable adhesion of the insole to any metal platen or press foot employed in assembling the shoe. A voltage, preferably alternating, above 3,000 volts, preferably 5,000-30,000 volts, is usually suitable, especially one having a frequency of LOGO-100,000 cycles per second. It is preferably a corona discharge but can be a spark or spray discharge. Preferably, both sides of the sheet are treated, with the electrodes situated, e.g., 0.005-0.2 inch away from the surfaces; and an application time of 0003-] second, especially 0.0l-0.5 second, is generally satisfactory.
The production of the articles of footwear can follow normal practice, although it is necessary to ensure that the degree of exposure to elevated temperatures, e.g., when using a hot melt adhesive, is not sufficient to cause collapse of the foam structure. This can generally be arranged where the necessary bonding between insole and other components of the shoe is achieved by means of a cold or hot melt adhesive or with a polyurethane or neoprene adhesive, or even by injection molding of a plasticized polyvinyl chloride sole and heel, provided that contact with elevated temperatures is maintained for as short a time as possible. It is, for instance, surprising that a polyamide or polyester hot melt adhesive can be used at 240 C. with an insole material having a softening temperature of only 120 C. or even less, if the period of time for which the insole is exposed to this temperature is not more than 5 seconds. Even better results in this respect can be obtained if the resin of the insole material contains a proportion of vinyl acetate at the lower end of the range, e.g., 3-7 percent or 3-5 percent by weight. Any metal platen or press foot maintained in contact with the insole during the process should normally be at a temperature lower than the softening point of the resin. Rubber vulcanizing is not generally a suitable method because of the excessive temperature/time cycles involved. Traditional methods can such as stitching or nailing can, of course, be employed.
The excellent flexibility of the insoles of the invention renders them particularly useful as components of ladies casual shoes and children s footwear, but they can also be very well employed in, e.g., men's shoes or boots, ladies court shoes, ladies fashion boots, or sports footwear for either sex.
It is obvious that many variations can be made in the products and processes set forth above without departing from the spirit and scope of this invention.
What is claimed is:
l. A process which comprises extruding a foamable resin composition wherein the resin is an ethylene-vinyl acetate copolymer or a blend thereof with polyethylene and has a polymerized vinyl acetate content of 2-l7 percent by weight through a die into a zone of lower pressure to form a foamed sheet having a substantially uniform thickness of 004-02 inch, a closed cell structure wherein at least percent of the cells are closed, and a density of 20-40 pounds per cubic foot, subjecting at least one side of the sheet to the action of an electric discharge for 0.0 1-0.5 second with electrodes situated 0.0050.2 inch away from the surfaces, the discharge being an alternating voltage of 5,000-30,000 volts with a frequency of l,000l00,000 cycles per second, and cutting the sheet into at least one insole-shaped piece.
2. The process of claim 1 wherein the insole-shaped piece is bonded to a heel board to form an assembly.
3. The process of claim 2 wherein an upper is bonded to the assembly and a sole and heel are then bonded to the underside of the assembly to form an article of footwear.
Claims (2)
- 2. The process of claim 1 wherein the insole-shaped piece is bonded to a heel board to form an assembly.
- 3. The process of claim 2 wherein an upper is bonded to the assembly and a sole and heel are then bonded to the underside of the assembly to form an article of footwear.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5232/68A GB1198552A (en) | 1968-02-01 | 1968-02-01 | Footwear. |
Publications (1)
Publication Number | Publication Date |
---|---|
US3624191A true US3624191A (en) | 1971-11-30 |
Family
ID=9792196
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US793559*A Expired - Lifetime US3624191A (en) | 1968-02-01 | 1969-01-23 | Footwear |
Country Status (5)
Country | Link |
---|---|
US (1) | US3624191A (en) |
DE (1) | DE1904892A1 (en) |
FR (1) | FR1600253A (en) |
GB (1) | GB1198552A (en) |
NL (1) | NL6901112A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4524529A (en) * | 1982-08-27 | 1985-06-25 | Helmut Schaefer | Insole for shoes |
US20070264520A1 (en) * | 2002-12-10 | 2007-11-15 | Wood Willard E | Articles having a polymer grafted cyclodextrin |
US20080103221A1 (en) * | 2004-11-08 | 2008-05-01 | Emanuela Alexandra Weinbeck | Crosslinked Polymer Foam Sheet and Process Therefor |
US20090094858A1 (en) * | 2007-10-11 | 2009-04-16 | Ungari Joseph L | Article of footwear with tubular sole assembly and method of manufacture |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1306373A (en) * | 1970-01-30 | 1973-02-07 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2565003A (en) * | 1947-03-17 | 1951-08-21 | Bata Narodni Podnik | Apparatus for the vulcanization of plastic materials |
US3080589A (en) * | 1955-06-10 | 1963-03-12 | Midgiey Shoe Systems Inc | Method of forming a laminated insole of varying thickness |
US3348251A (en) * | 1965-01-22 | 1967-10-24 | United Shoe Machinery Corp | Shoe manufacturing |
US3379802A (en) * | 1964-11-04 | 1968-04-23 | Dow Chemical Co | Foamed olefin copolymer blends |
-
1968
- 1968-02-01 GB GB5232/68A patent/GB1198552A/en not_active Expired
- 1968-12-31 FR FR1600253D patent/FR1600253A/fr not_active Expired
-
1969
- 1969-01-23 NL NL6901112A patent/NL6901112A/xx unknown
- 1969-01-23 US US793559*A patent/US3624191A/en not_active Expired - Lifetime
- 1969-01-31 DE DE19691904892 patent/DE1904892A1/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2565003A (en) * | 1947-03-17 | 1951-08-21 | Bata Narodni Podnik | Apparatus for the vulcanization of plastic materials |
US3080589A (en) * | 1955-06-10 | 1963-03-12 | Midgiey Shoe Systems Inc | Method of forming a laminated insole of varying thickness |
US3379802A (en) * | 1964-11-04 | 1968-04-23 | Dow Chemical Co | Foamed olefin copolymer blends |
US3348251A (en) * | 1965-01-22 | 1967-10-24 | United Shoe Machinery Corp | Shoe manufacturing |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4524529A (en) * | 1982-08-27 | 1985-06-25 | Helmut Schaefer | Insole for shoes |
US4575446A (en) * | 1982-08-27 | 1986-03-11 | Helmut Schaefer | Process for producing an insole for shoes |
US20070264520A1 (en) * | 2002-12-10 | 2007-11-15 | Wood Willard E | Articles having a polymer grafted cyclodextrin |
US20080103221A1 (en) * | 2004-11-08 | 2008-05-01 | Emanuela Alexandra Weinbeck | Crosslinked Polymer Foam Sheet and Process Therefor |
US20090094858A1 (en) * | 2007-10-11 | 2009-04-16 | Ungari Joseph L | Article of footwear with tubular sole assembly and method of manufacture |
US7926204B2 (en) | 2007-10-11 | 2011-04-19 | Nike, Inc. | Article of footwear with tubular sole assembly and method of manufacture |
US20110154584A1 (en) * | 2007-10-11 | 2011-06-30 | Ungari Joseph L | Article of footwear with tubular sole assembly and method of manufacture |
US8650690B2 (en) | 2007-10-11 | 2014-02-18 | Nike, Inc. | Article of footwear with tubular sole assembly and method of manufacture |
Also Published As
Publication number | Publication date |
---|---|
DE1904892A1 (en) | 1969-09-04 |
GB1198552A (en) | 1970-07-15 |
NL6901112A (en) | 1969-08-05 |
FR1600253A (en) | 1970-07-20 |
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