WO1999006495A1

WO1999006495A1 - Object with improved grip

Info

Publication number: WO1999006495A1
Application number: PCT/FR1998/001642
Authority: WO
Inventors: Ludwik Leibler; Pascale Fabre; Guillaume De Crevoisier; Jean-Marc Corpart
Original assignee: Elf Atochem S.A.
Priority date: 1997-07-31
Filing date: 1998-07-24
Publication date: 1999-02-11
Also published as: FR2766833B1; AU8868098A; EP1000126A1; FR2766833A1; JP2001512171A

Abstract

The invention concerns an object with improved grip, whereof at least one part designed to be in contact with the hand is coated with an effective amount of a polymer further comprising a main chain, lateral perfluoroalkyl groups and lateral alkyl groups, and having a melting temperature ranging between 25 and 45 °C, preferably between 25 and 37 °C.

Description

IMPROVED GETTING STARTED

The present invention relates to objects having an improved grip, and a method of manufacturing said objects. By taking hold (or, equivalently, holding hand) of an object by a person, the fact for this person to communicate to him, by means of one or both hands, an impulse and / or various movements involving a certain force, typically greater than 1 N. This force can either be the weight of the object, increased by the force linked to the acceleration that the person wishes to communicate to the object, or the pulling force exerted by the person who stands at the object in order to ensure his own balance. It is important that, in all these situations, the contact between the object and the hand (s) of the person who holds the said object or who stands on the said object, is facilitated by a certain grip, in order to improve the grip. said object and limit the risk of hand slipping. It will therefore be understood that we also mean by taking hold of an object, the fact for a person to grasp this object by one of its parts, the contact between said part and the hand operating through the internal face of the hand, including the palm, possibly via a glove. We can give as examples of situations where it is important to have a good grip on objects, the field of handling tools, and that of all sports where the action of play stages an object whose good handling is essential to ensure a good result (tennis, golf, windsurfing, water skiing). We understand this fact better by referring to a particular sport such as tennis or golf, where we understand that the leather or rubber coating deposited on the handle of the racket or cane must be non-slip so as to better ensure that it is taken by the player. We can also cite as an example of an object to which a person stands, in order to ensure his own balance, the part of a windsurf board called "wishbone" in English. In such a case, in order to obtain good adhesion, several methods have been proposed in the past and surface treatments have been developed. Patent application WO 94/19414 recommends, for example, the use of a mixture formed from an ethylene-vinyl acetate copolymer, a natural or synthetic lubricant and a tackifying agent. Emulsions containing a tackifying resin on a polyolefin base (JP 08-17356) or acrylic polymers (patent FR 2 192 567) have also been proposed for the treatment of surfaces. From a different perspective, the production of synthetic leather based on leather powder, a binder and a tackifying resin has also been envisaged. For example, in patent JP 04-077250, the manufacture of recomposed leather containing 5 to 60% of leather powder and 40 to 95% of synthetic resin has been proposed. In all cases, if these formulations make it possible to provide increased adhesion to substrates, they have a certain number of drawbacks, in particular related to the storage of the material concerned. Thus, these formulations can lead to problems of accelerated fouling of the substrate, on which the dust will remain stuck or to an unwanted adhesion of the treated object, on other objects stored with it. It has also been proposed to use additives of the semi-crystalline acrylic polymer type in pressure-sensitive adhesives (PSA) (see for example US Pat. No. 5,412,035 and R. Clarke et al., Adhesive age 36, p 39, Sept. 1993). The incorporation into these systems of semi-crystalline acrylic polymers carrying side groups of the long alkyl chain type (with a number of carbon atoms greater than or equal to 12) makes it possible to obtain melting temperatures in a range ranging from 0 to 60 ° C. Above the melting temperature, the polymer adheres. Below this temperature, it does not adhere. This type of PSA with a melting temperature of around 30 ° C is, for example, used to fix dressings on the skin. The dressings are then easily removed by decreasing the temperature below 30 ° C. These documents, however, in no way suggest the problem of handling objects, as mentioned above, whether they are tennis racket sleeves or windsurf wishbones. In addition, the chemical structures used have the disadvantage of not being sufficiently resistant to water to be usefully used. Similarly, their low resistance to perspiration, body fluids or solvents limits their interest in possible applications other than in the medical field. However in the field of sports, it is important to ensure a good grip of the objects mentioned above including in a humid environment: whether it is the perspiration of the sportsman, or, for outdoor sports, the rain, or in the case of windsurfing, the spray. It has now been found that it is possible to obtain objects having an improved grip, even when these are used in a humid atmosphere, and also having remarkable properties of resistance to fouling.

The present invention therefore relates to an object having an improved grip, of which at least a portion intended to be in contact with a hand is coated with an effective amount of a polymer comprising, in addition to a main chain, perfluoroalkyl side groups and alkyl side groups, and having a melting temperature between 25 and 45 ° C, preferably between 25 and 37 ° C. The melting temperatures mentioned in the present text are measured by differential scanning calorimetry using the following cycle: temperature rise from -30 ° C to + 130 ° C; temperature decrease from + 130 ° C to -80 ° C and second temperature rise from -80 ° C to + 130 ° C, all with a speed of 10 ° C / min. The melting point is measured during the second temperature rise. For the purposes of this text, the melting temperature is the lowest temperature observed, corresponding to the minimum of an endothermic peak.

The objects according to the present invention offer an excellent grip thanks to a good adhesion between the hand, or the hand covered with a glove, and the concerned part of the object, even in wet or rainy weather. When the hand is removed from the object, the latter is advantageously free from any trace of adhesive, and the object no longer exhibits adhesive properties. Thus, the objects according to the invention exhibit, when they are not held in the hand, very good resistance to fouling, in particular by dust.

The structure of the main chain of the polymer can be extremely varied, and can in particular be of the polysiloxane, poly (meth) acrylic, polyvinyl, polystyrenic, polyester, polyphosphazene, polyamide, poly (meth) acrylamide type.

A main chain is a poly (meth) acrylic type chain.

The length of the perfluorinated side groups is advantageously from 5 to 20 carbon atoms, preferably from 7 to 15. Preferred are polymers in which the perfluorinated side groups are attached to the main chain of the polymer by a divalent group - (CH ₂ ) _m -, m being an integer between 1 and 12, preferably equal to 2.

The alkyl side groups have a length of between 12 and 30 carbon atoms, preferably between 14 and 20. In the main chain of the polymer used, it is also possible to introduce a unit not carrying a side group, such as an N-methylolacrylamide, ethylene or vinyl chloride type unit.

According to a preferred variant of the objects according to the present invention, the part of the latter which is intended to be in contact with a hand, is coated with a polymer in which the proportion of the lateral groups of the perfluoroalkyl type (expressed in% of the total of the number of lateral groups) is between 20 and 70%, preferably between 30 and 60%.

Finally, the polymers used advantageously have a tack energy measured at 35 ° C of between 1 and 1000 J / m ² , preferably between 10 and 100 J / m ² . The term “tack energy” is understood to mean the energy (referred to the surface unit), necessary for the separation of 2 surfaces which have been brought into contact by means of an adhesive for a short time, typically a few seconds and under the action of low pressure, typically a few tenths of megapascals. This energy is measured at by means of a prism pegimeter, by determining, at a fixed temperature, the energy necessary to take off an aluminum plate treated with said polymer, previously brought into contact with the prism by exerting a pressure of 0.35 MPa during a duration of one second. The objects according to the invention are preferably chosen from tools and sporting articles such as tennis rackets, table tennis, squash, badminton, golf clubs, windsurf wishbones, shuttlecocks of cars. In most cases, the part of these objects intended to be in contact with a hand is therefore the handle. Particularly preferred are golf clubs.

The polymers used in the objects according to the invention are prepared according to methods well known to those skilled in the art. Mention may in particular be made of the copolymerization in solution or in emulsion of the appropriate monomers, or else the chemical modification of the main chain of a polymer, to introduce the fluoroalkyl and alkyl side groups, using grafting techniques.

The quantity of polymer with which the part of the object intended to be in contact with a hand is coated can vary within wide limits. It is generally between 0.05 and 100 g / m ² of the surface concerned, preferably between 0.25 and 20 g / m ² .

The present invention also relates to a method intended to improve the handling of objects, characterized in that an effective quantity of a polymer as defined above is applied to the part of said object intended to be in contact with a hand .

The polymer can be applied by numerous and variable methods depending on the nature of the support to be treated. The polymers presented in solution or in emulsion can in particular be deposited on the supports by spraying, by application by brush or by brush, by soaking in a bath. For certain substrates, more specific methods can be used such as, for example, padding or foaming for textiles or fulling for leather. It is generally necessary to carry out a drying which can be carried out at a temperature ranging from ambient to 200 ° C., but it is preferred to dry at ambient temperature.

The polymer is generally applied by means of a liquid comprising from 0.5 to 10% by weight of said polymer.

In the event of a significant drop in performance, the treatment is perfectly renewable with a new application. Media of all kinds can be processed. Mention may in particular be made of metals, fabrics, nonwovens, plastics, leather, paper, building materials, wood. Without limiting its scope, the invention is now illustrated by the following examples in which the parts indicated are expressed by weight, unless otherwise indicated.

In these examples, the water resistance and the oleophobicity of the treated supports are evaluated by the following tests.

Water resistance tests:

The test described in the standard "American Association of Textile Chemists and Colorists (AATCC) Technical Manual", test method 22 (1992) assesses the resistance to wetting of treated fabrics by water. 250 ml of water are poured from a height of 15 cm, via a funnel ending in an aluminum sprinkler, onto the fabric sample stretched over a frame with a diameter of 15.2 cm and inclined at 45 °. When all the water has been poured out, the frame is tapped on a hard surface to remove the excess water and the level of wetting is visually noted in relation to a series of 6 values indicated on a photographic reference published in the standard. The table indicates the rating of the test according to the level of wetting:

Oleophobia tests:

Oleophobia is measured, on textiles, according to the test described in the standard "AATCC" Technical Manual ", test method 118 (1992) which assesses the non-wettability of the substrate by a series of oily liquids whose surface tensions are The rating of the treated substrate is defined as the value of the maximum test liquid which does not wet the support after a contact time of 30 seconds The test liquids used in the evaluation are listed in the following table:

EXAMPLE 1

In a reactor of 1000 parts by volume, heated by a thermostated double jacket and provided with anchor stirring and a reflux condenser, the following were introduced:

- 425 parts of butyl acetate

- 47 parts of a mixture of poly fluorinated acrylates of general formula:

C _n F ₂ n + ιC ₂ H ₄ O-CO-CH = CH ₂

(n is equal to 8, 10, 12 and 14 in the respective weight ratios of 63, 25, 10, and 2) and

- 28 parts of stearyl methacrylate

After inerting with nitrogen and heating to 70 ° C., the polymerization was initiated by the addition of 1.5 parts of azo-2,2'-bis-isobutyronitrile. After 6 hours of polymerization, the mixture was allowed to cool and a clear solution (SI) comprising 15% by weight of copolymer according to the invention was obtained.

This copolymer has a tack energy of 16 J / m ² at 35 ° C, and 0 J / m2 at 30 ° C. It has a melting point of 35 "C.

By way of comparison, a homopolymer of stearyl methacrylate was prepared under identical synthesis conditions, and a homopolymer solution (Sa) was obtained. The melting point of polymethacrylate of stearyl is 33.6 ° C, comparable to that of the previous copolymer.

Solutions (SI) and (Sa) are applied by spraying onto the rubber coating of a golf club, at a rate of 10 g / m ² of polymer. We see that the grip is actually improved. The solution (SI) is applied to a 100 cm ² rubber sheet at a rate of 10 g / m ² . This rubber sheet is brought into contact with a normally dusty soil surface. It can be seen that the rubber sheet is not very dirty.

The properties of resistance to water and to solvents conferred by (SI) and (Sa) are very different. The two solutions diluted in butyl acetate are applied by spraying onto a mixed polyamide / cotton fabric to a concentration of 1% of polymer, corresponding to an amount of polymer of 0.25 g / m ² .

After drying, the results listed in the following table are obtained:

Rating 0 of the oleophobia test means that the substrate is wetted by the 8 test liquids, that is to say that the substrate corresponding to this rating is less oleophobic than a substrate of rating 1 to 8.

EXAMPLE 2

In the same reactor as in Example 1, the following were introduced: 375 parts of demineralized water,

- 135 parts of acetone,

- 13.2 parts of trimethyl oleyl ammonium chloride,

- 12.1 parts of a mixture of oxyethylenated alkylphenols of HLB equal to 15,

- 136.8 parts of the same mixture of polyfluorinated acrylates as in Example 1, - 130.7 parts of stearyl methacrylate,

14.9 parts of N-methylolacrylamide in 48% solution in water, and

- 0.27 parts of n-dodecylmercaptan.

After inerting with nitrogen and heating to 65 ° C., the polymerization was initiated by the addition of 2 parts of azo-bis hydrochloride (amidinopropane). After 3 hours of polymerization, the acetone was distilled, then diluted with water so as to obtain an emulsion containing 20% of dry extract.

The copolymer thus synthesized has a melting point of around 30 ° C.

The coating obtained has a tack energy of the order of 12 J / m ² for a temperature above 30 ° C while it is zero for a lower temperature. The emulsion is applied by spraying on the leather covering of the handle of a tennis racket. Drying is carried out in a few minutes at room temperature.

The tennis racket thus treated has a very good grip, including in rainy weather, and a good resistance to fouling by dust when stored at room temperature. The hydrophobic and oleophobic properties of the racket handle are excellent.

Claims

1. Purpose having improved hand held in, at least a portion _^ intended to be in contact with a hand is coated with an effective amount of a polymer further comprising a main chain, perfluoroalkyl side groups and alkyl side groups , and having a melting temperature between 25 and

45 ° C, preferably between 25 and 37 ° C.

2. Object according to claim 1, characterized in that the main chain of the polymer is a poly (meth) acrylic type chain.

3. Object according to one of claims 1 or 2, characterized in that the length of the perfluorinated side groups is from 5 to 20 carbon atoms, preferably from 7 to 15.

4. Object according to one of claims 1 to 3, characterized in that the perfluorinated lateral groups are attached to the main chain of the polymer by a divalent group - (CH ₂ ) _m -, m being an integer between 1 and 12 , preferably equal to 2.

5. Object according to one of claims 1 to 4, characterized in that the alkyl side groups have a length of between 12 and 30 carbon atoms, preferably between 14 and 20.

6. Object according to one of claims 1 to 5, characterized in that the proportion of lateral groups of perfluoroalkyl type is between 20 and 70%, preferably between 30 and 60%.

7. Object according to one of claims 1 to 6, characterized in that the polymer has a tack energy, measured at 35 ° C, between 1 and 1000 J / m ² , preferably between 10 and 100 J / m ² .

8. Object according to one of claims 1 to 7, characterized in that the quantity of polymer which is coated with the part of the object intended to be in contact with a hand, is between 0.05 and 100 g / m ² of the surface concerned, preferably between 0.25 and 20 g / m ² .

9. Object according to one of claims 1 to 8, characterized in that it is chosen from tools and sporting goods.

10. Golf club according to one of claims 1 to 9.

11. A method intended to improve the handling of objects, characterized in that an effective amount of a polymer as defined in one is applied to the part of said object intended to be in contact with a hand. of claims 1 to 7.

IMPROVED GETTING STARTED

Object having improved grip, at least part of which is intended to be in contact with a hand, is coated with an effective amount of a polymer comprising, in addition to a main chain, perfluoroalkyl side groups and alkyl side groups, and having a melting temperature between 25 and 45 ° C, preferably between 25 and 37 ° C.