EP3433418A1

EP3433418A1 - Process for selecting a compound for one of the layers of a carpet

Info

Publication number: EP3433418A1
Application number: EP17713741.1A
Authority: EP
Inventors: Bernard GUIRAUD; Gilles Guillaume
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-03-23
Filing date: 2017-03-09
Publication date: 2019-01-30
Also published as: WO2017162952A1; FR3049290B1; FR3049290A1

Abstract

Process for selecting a composition that gives the covering obtained from said polyolefin the dimensional stability and distortion properties defined according to the standard NF EN 1307 and measured according to the standard NF EN 986, characterized in that the composition is selected when the ratio between the complex shear modulus at the temperature of 40°C and the complex shear modulus at the temperature of 100°C is greater than 50 (G* 40°C / G* 100°C > 50) and when the start of the increase in cohesion of the composition takes place at a temperature above 60°C.

Description

METHOD FOR SELECTING A COMPOUND FOR ONE OF THE LAYERS OF A CARPET

The present invention relates to the field of floor coverings, carpet type synthetic material, and preferably in the form of slabs. The invention relates to carpets of the type comprising at least, successively:

a contact layer intended to be placed towards the user, also called the wear layer, generally made of polyamide, polyester or polypropylene fibers stitched onto a polyester fiber backing;

an anchoring layer, usually called precoat anglicism, which consolidates the backing with the wear layer, this layer being a pre-coating material most often based on SBR (styrene-butadiene copolymer) latex; and

- At least one support layer or hung to rest, or be fixed on the floor, also called upside down, usually nonwoven polyester or needle-punched polyester or polyurethane foam. The carpets obey various constraints to meet the requirements of users. They must be both:

comfortable (contact and flexibility),

easy maintenance,

resistant to wear,

- able to dampen noises,

thermally insulating.

dimensionally stable In addition, it also seeks to avoid the problem of the characteristic smell of new carpet, which is often disturbing. This disadvantage is due to the SBR polymerization of the SBR latex layer which results in the presence of a polymerization by-product 4-PCH (4-phenyl-cyclohexene).

It is now proposed to replace the SBR latex layer with a polyolefin. This material does not emit any odor and has many advantages: it lowers VOC emissions (volatile organic compounds) considerably, it is easy to coat, the coating process provides a reduced consumption of energy, its recycling is easier, and it has hydrophobic properties preventing water from passing through the anchoring layer when cleaning carpets and thus avoiding the development of bad odors related to the proliferation of bacteria.

The use of a polyolefin is described in particular in patent EP1375731, more specifically the composition is based on a substantially amorphous poly-alpha-olefin having a melting enthalpy of at least 2J / g and at most 100 J / g, and a melt viscosity at 190 ° C (according to DIN 53019) in the range of 200 to 20,000 mPa s.

This composition is selected by presenting specific viscosity values to facilitate its coating on the backrest, and thus facilitate the process of manufacture of the carpet.

If the use of a polyolefin is particularly advantageous for the reasons mentioned above, this material must be able to give the carpet the same requirements of SBR latex with regard to the dimensional stability of the final product and the performance of use.

Indeed, if such a material is suitable for carpets in large width, it is necessary that it is also suitable for modular format carpets such as slabs.

However, it is essential that the carpet tiles have the properties of dimensional stability and lack of curvature for one hand to allow their layout on the ground without using glue and prevent over time the movement of slabs and the opening of the joints between adjacent slabs, and secondly guarantee over time their flatness by a reduced sensitivity to thermal and hygrometric variations in ambient atmosphere.

The object of the invention is therefore to propose a method of selecting a composition which does not have the disadvantages of the SBR latex and makes it possible to confer on the coating obtained from said component the dimensional stability and curvature properties measured according to the standard NF EN 986 and conform to the requirements defined in standard NF EN 1307.

With regard to the NF EN 986 standard, the dimensional stability is evaluated through the dimensional variations of the edges of a slab during successive test steps which are:

1. 48 hours at 20 ° C under 65% hygrometry,

2. 2 hours in an oven at 60 ° C,

3. 2 hours in a tray of water at 20 ° C,

4. 24 hours in an oven at 60 ° C,

5. 48 hours at 20 ° C under 65% hygrometry. Thus, at the end of each of these steps 2 to 5, the dimensional variations of the slab tested, firstly in the longitudinal direction of the slab (plane of the general surface of the slab) and secondly according to the transverse direction, must be less than + or - 0.20%, and at the end of the final step 5, the flatness of the product must be less than + or -2 mm with respect to a reference plane corresponding to the support plane of the slab. According to the invention, the method for selecting a composition conferring on the coating obtained from said composition dimensional stability and curvature properties, in particular the properties of dimensional stability and curvature being defined according to the NF EN standard. 1307 and measured according to standard NF EN 986, is characterized in that the composition is selected when the ratios between the complex shear modulus at a temperature of 40 ° C. and the complex shear modulus at a temperature of 100 ° C. is greater at 50 (G * ₄ ° C / G * -10 ° C> 50) and when the beginning of the cohesion increase occurs at a temperature above 60 ° C.

It is recalled that the rise in cohesion is representative of a change in the rheological state of the composition / material from a certain temperature, which results in a sharp increase in the rigidity of the material. It is visualized on a curve representing the evolution of the shear modulus as a function of temperature and is characterized in a known manner by a change of slope of the curve.

The inventors have surprisingly demonstrated that the combination of the technical characteristics or the two criteria of the increase in cohesion and the ratio between the shear moduli temperatures of 40 ° C and 100 ° C, was of great importance and allowed to ideally select the appropriate composition to obtain dimensional stability and curvature of the coating satisfying the above requirements, especially the standard.

The invention also relates to a method for obtaining / manufacturing a carpet covering comprising a tuft-type layer of fibers intended to constitute the wear layer on which the user will walk, and an anchoring layer. applied on the fiber layer, characterized in that the anchoring layer consists of a composition such that the ratios between the complex shear modulus at a temperature of 40 ° C and the complex shear modulus at the temperature of 100 ° C is greater than 50 (G * ₄ o ° c / G * -iooo ° c> 50) and the beginning of the increase in cohesion occurs over a temperature range greater than 60 ° C.

The method for obtaining / manufacturing a carpet covering comprising a layer of tuft-type fibers, called the wear layer, and at least one anchoring layer applied to the wear layer is implemented by having previously performed the selection process to select the composition of the anchor layer.

The selection process comprises a step of measuring the complex shear modulus of the composition over a temperature range greater than room temperature, in particular over a temperature range between at least 20 ° C or 40 ° C and 180 ° C, and calculating the shear modulus ratio at 40 ° C and 100 ° C and comparing the ratio with the value 50.

In addition, the method advantageously comprises the study of the increase in cohesion of the composition from the measurements of the complex shear. The beginning of the cohesive rise corresponds to the part of the curve of measurements of the complex shear modulus as a function of temperature, for which a first abrupt change of slope is observed.

The complex shear modulus is measured in a known manner using a rheometer, for example of the MCR 301 type sold by the company Anton-Paar, and using a geometry with parallel planes of diameter 25 mm and gap 1 mm. The sample to be characterized, in solid form, is shaped directly on the system at 160 ° C, with the appropriate accessories. The measurement consists of applying to the sample a dynamic stress (oscillatory mode), with imposed deformation (0.05%), at a frequency of 1 Hz. The sample thus subjected is subjected to a temperature cooling of 160 °. C at 30 ° C with a ramp of -2 ° C / min.

According to the invention, the selected composition is used for the manufacture of carpet tiles as removable slabs. A removable lead slab meets the NFEN 1307 standard.

According to one characteristic, the composition has a viscosity of the order of between 1 Pa s and 10 Pa s, at 150 ° C., the viscosity being measured by a Brookfield viscometer at a shear rate of 1.68 s ^-1 . According to a preferred composition, the composition comprises, as essential compound, a polyolefin, preferably a poly-α-olefin, in particular chosen from an atactic polypropylene (APP), a poly-1-butene atactic, a propene / ethene copolymer, a copolymer propene / 1-butene, a 1-butene / ethene copolymer, a propene / 1-butene / ethene terpolymer. The composition of the invention for constituting the anchoring layer may comprise additional compounds in addition to the main compound in order to adapt the ratio of the shear moduli of the composition and to obtain an onset of cohesion at more than 60 ° C. , to achieve the desired selection. By way of example, the additional compounds are wax such as the commercial reference shell microcrystalline HMP or Multivax A80MH. The anchoring layer of the carpet comprises in particular:

a polyolefin,

a material having a low melt viscosity, such as of the order of 0.01 Pa.s at 120 ° C. and at most 0.1 Pa.s at 120 ° C., in particular a Fisher-type wax; Tropsch,

optionally mineral fillers of the calcium carbonate type, this total composition satisfying the criteria for selecting the ratio of the shear moduli according to the process of the invention. The wear layer (on which is affixed in the method of manufacture the anchor layer) includes fibers, filaments or the like, of a polymeric material, such as polyamide, polyester, polypropylene or wool, associated with a base matrix generally polyester through a known manufacturing process, for example the most common that called "tuft".

The carpet further comprises, between the anchor layer and the support layer:

- A reinforcing layer, in the form of a fabric made from glass fibers or polyester; an adhesive bonding layer comprising at least one material with an adhesive property. This bonding layer serves in particular to confer acoustic properties and comfort.

The adhesive bonding layer comprises:

preferably a poly-alpha-olefin that is almost completely amorphous (at least 40% by weight), such as, for example, Vestoplast 508 marketed by Evonik®;

- charges in proportion between 50 and 80% such as CaCO 3, MgO 3;

an adhesive composition (for at least 10% by weight), comprising, for example, tackifying resin, such as the product Escorez 1401 marketed by Exxon Chemicals, and / or wax, and / or paraffin, and which can comprise one or more functional components such as antioxidants, dyes, antibacterial agents ...

Preferably, the adhesive composition of the adhesive bonding layer between the anchoring layer and the support layer is such that:

the ratio of the shear modules G * at the temperature of 40 ° C. and at the temperature of 100 ° C. (G * ₄₀ ° C./G * 100 ° C.) is greater than 50, and preferably greater than 100, and still more preferred greater than 500;

- The shear modulus at 70 ° C G * 70 ° c is greater than 0.1 MPa.

The support or hanging layer intended to rest, or be fixed on the ground, is in known manner non-woven polyester or needle-punched polyester or polyurethane foam or polypropylene. The invention also relates to a method of manufacturing a carpet covering, in particular carpet tiles, comprising at least the steps of:

make a wear layer, intended to be disposed towards the user when using the carpet;

make an anchoring layer, usually called "precoat" anglicism;

performing at least one other layer, said support layer or hooked for resting, or be fixed on the floor when using the carpet;

assemble or join the layers above one above the other;

characterized in that the anchoring layer is made of a composition selected according to the selection method of the invention.

The anchoring layer is applied in known manner by any application method, for example by coating via a roller-coater or a doctor blade application, preferably at a temperature of 180 ° C. The present invention is now described with the aid of examples which are only illustrative and in no way limitative of the scope of the invention, from the following figures:

Figure 1 is a schematic view along a vertical plane of a carpet of the invention.

FIG. 2 illustrates the curves of the complex shear modulus G ^* measured over the temperature range between 40 ° C. and 160 ° C. for an exemplary composition of the invention and a comparative example. Referring to Figure 1, there is shown a schematic sectional view of an example of carpet floor covering, carpet type carpet. The represented carpet successively comprises:

a contact layer or so-called 1, intended to be arranged towards the user;

an anchoring layer 2, usually called "precoat" anglicism;

- A reinforcing layer 3, in the form of a fabric made from glass fibers or polyester;

an adhesive bonding layer 4;

a support or hanging layer 5, intended to rest, or be fixed on the ground, non-woven polyester or needle-punched polyester or polypropylene.

The carpet, more particularly the carpet tile, of the invention has the properties of a removable lead plate; it has the dimensional stability and curvature properties defined by standard NF EN 1307 and determined / measured according to standard NF EN 986.

The wear layer 1 includes fibers 6, filaments or the like, made of a polymeric material, such as a polyamide, a polyester or wool, associated with a polyester base matrix 7. The incorporation of the fibers 6 in the matrix 7 is carried out by any known method, the most common being called "tuft".

The wear layer 1 is preferably made of polyamide. Said anchoring layer 2 is selected according to the method of the invention which is described below. This layer is based on a polyolefin and has a start and cohesion at a temperature above 60 ° C.

By way of example, the anchoring layer 2 comprises:

a poly-alpha-olefin,

a material having a low melt viscosity, such as a Fisher-Tropsh type wax, of the order of 0.01 Pa s at 120 ° C. and at most 0.1 Pa s at 120 ° C. C, and o optionally a mineral filler of calcium carbonate type.

The adhesive tie layer 4 comprises materials and compounds intended to provide the carpet with the required properties of comfort of use and acoustic damping.

For this purpose, the adhesive bonding layer comprises, for example:

a poly-alpha-olefin that is almost completely amorphous (at least 40% by weight), such as, for example, Vestoplast 508 sold by Evonik®;

an adhesive composition (for at least 10% by weight), comprising tackifying resin, such as the product Escorez 1401 marketed by Exxon Chemicals, and / or wax, and / or paraffin, and preferably other functional components of the type antioxidants, dyes, antibacterial agents ...

Preferably, said adhesive composition is such that:

the ratio of the shear modules G * at the temperature of 40 ° C. and at the temperature of 100 ° C. (G * ₄₀ ° C./G * 100 ° C.) is greater than 50, and more preferably greater than 100, and even more preferably greater than 500;

- the shear modulus at 70 ° CG ^* 7o ° c is greater than 0, 1 Mpa.

By way of example, the adhesive composition having these characteristics relating to the shear modulus is made of:

- 25% of Vestoplast 508,

- 4% of Escorez 1401,

1% microcrystalline wax having a melting point greater than 60 ° C.,

- 70% CaCO ₃ .

The method for selecting the composition of the anchoring layer according to the invention consists in selecting a composition whose ratio between the complex shear modulus at a temperature of 40 ° C. and the complex shear modulus at a temperature of 100 ° C. C is greater than 50 By way of example, a composition selected according to the process of the invention is the VESTOPLAST EP403 material marketed by EVONIK® which is a poly-alpha-olefin to which 5% of microcrystalline HMP wax sold by EXXON Chemicals has been added. A comparative example is the product VESTOPLAST EP403 as such.

The viscosities at 150 ° C. and 180 ° C. of the compositions of the example of the invention and the comparative example are as follows: Viscosity Viscosity

150 ° C 180 ° C

Example of the invention 7.1 Pa s 3 Pa s

Comparative Example 8, 8 Pa s 4.3 Pa s

FIG. 2 illustrates the curves of the complex shear modulus G ^* measured over the temperature range between 40 ° C. and 160 ° C. for the example of the invention and the comparative example.

From the measurements of the complex shear modulus is calculated the ratio G * ₄ o ° c / G * ioo °.

For the example of the invention, VESTOPLAST EP403 to which was added 5% of wax: G * ₄₀ ° c / G * 100 ° = 3199,

which meets the selection criterion of the invention.

In addition, the curve shows a rise in cohesion. This cohesion takes place over a range from 68 ° C to 91 ° C. The beginning of the cohesive rise is the abrupt change in the slope of the curve. To facilitate reading, the lines corresponding to the significant changes of slopes of each curve have been drawn. The first point of intersection of two lines of different slopes corresponds to the beginning of the cohesion of the material. This increase in cohesion for the example of the invention starts beyond 60 ° C, close to 70 ° C.

For the comparative example, VESTOPLAST EP403: G * ₄₀ ° c / G * 100 ° = 819, which meets the first selection criterion of the invention. However, it can be seen from the curve that the onset of cohesion is at 45, which does not meet the second criterion of the invention. It will be seen later that the comparative example does not just achieve the results imposed in terms of dimensional stability and curvature. The tables below summarize the results of measurement of dimensional stability and curvature of slabs of 50 cm by 50 cm whose anchoring layer (precoat) was made from the above examples respectively of the invention. and comparative. The manufacture of the slabs was identical, with an application of the precoat with the doctor blade.

The stability measurements were made according to standard NF EN 986 at different temperatures and for three samples of the same slab for each type of measurements according to the different test steps.

The curvature measurements were made according to standard NF EN 986 for the same three samples of the slab. The data in the tables below corroborate the effective implementation of the method of the invention to ensure the dimensional stability and curvature of a carpet tile when it is made from a carpet layer. anchoring meeting the selection criteria of said method.

Table I dimensional stability of a slab from the example of the invention: Differences in% with requirement of

+ or - 0.20%

N ° of 2h in 2h 24h 48h at 20 ° C the oven sample in under 65% with the water oven of hygrometry

60 ° C to

20 ° C 60 ° C

1 Longitudinal direction -0.07 -0.07 -0.14 -0.16

1 Transverse direction -0,03 -0,01 -0,04 -0,06

2 Longitudinal direction -0,08 -0,18 -0,1 -0,1 1

2 Transverse direction -0,03 -0,06 -0,05 -0,07

3 Longitudinal Direction -0,07 -0,12 -0,06 -0,04

3 Transverse direction -0.04 -0.07 -0.03 0

It is found that the slab manufactured from the example of the invention meets the requirements of the standard which is a shrinkage or elongation of less than 0.20%.

Table II of curving a slab from the example of the invention:

Requirement number of 2 mm deviation for the slab sample considered before testing and after passing the last test

1 Longitudinal Direction 0

1 Transverse direction 0

2 Longitudinal 0

2 Transverse direction 0

3 Longitudinal Direction 0

3 Transverse direction 0 It is found that the slab manufactured from the example of the invention meets the requirements of the standard which imposes a slump of less than 2 mm, since the measurements show that there is no sag. Table III dimensional stability of a slab from the comparative example:

Table IV curve of the slab from the comparative example:

Requirement no difference of at most 2 mm for the slab considered before the tests and the sample

after passing the last test

1 Longitudinal Direction 0

1 transverse direction 5

2 Longitudinal 0

2 Transverse direction 4

3 Longitudinal Direction 0

3 Transverse direction 4 It is noted that the slab made from the composition of Comparative Example VESTOPLAST EP403 does not meet the requirements of the standard.

Although the composition of comparative example VESTOPLAST EP403 does have a viscosity suitable for its coating (the viscosities are indicated above for the examples of the invention and comparative), it does not make it possible to obtain the required properties of dimensional stability and lack of curvature for carpet especially for carpet tiles.

Therefore, the inventors propose a method of selecting a composition precoat carpet that is simple to implement and is performed independently of the manufacture of the carpet. Thus, well upstream, it is possible to select the appropriate composition which will make it possible to obtain the results of dimensional stability and curvature of the final product, based on measurements of the complex shear modulus as a function of the temperature and the estimate. from the start of cohesion rise of the composition.

Claims

1. A method of selecting a composition imparting to the coating obtained from said polyolefin dimensional stability and curvature properties, characterized in that the composition is selected when the ratio of the complex shear modulus to the temperature of 40 ° C and the complex shear modulus at the temperature of 100 ° C is greater than 50 (G * ₄ ° C / G ^* 100 ° C> 50), and when the beginning of the cohesive rise of the composition occurs above 60 ° C.

2. Selection process according to claim 1, characterized in that it comprises a step of measuring the complex shear modulus over a temperature range greater than room temperature, in particular over a temperature range between at least 20 ° C. or 40 ° C and 180 ° C, and calculating the ratio of the shear modules at the temperature of 40 ° C and 100 ° C, and the comparison of the ratio with the value 50.

3. A method of selection according to the preceding claim, characterized in that it comprises the study of the cohesion of the composition from measurements of the complex shear modulus.

4. Selection process according to any one of the preceding claims, characterized in that the composition comprises as essential compound a polyolefin, preferably a poly-alpha-olefin, in particular chosen from an atactic polypropylene (APP), a poly- 1-butene atactic, a propene / ethene copolymer, a propene / 1-butene copolymer, a 1-butene / ethene copolymer, a propene / 1-butene / ethene terpolymer.

5. Selection process according to any one of the preceding claims, characterized in that the composition has a viscosity of the order between 1 Pa s to 10 Pa s.

6. Selection process according to any one of the preceding claims, characterized in that it comprises a polyolefin as a main component, a second component having a low melt viscosity such as of the order of 0.01. Pa s and at most 0.1 Pa s at 120 ° C, including a Fisher-Tropsh type wax, and possibly mineral fillers of calcium carbonate type.

7. A process for obtaining a carpet covering comprising a layer of tuft-type fibers, called the wear layer (1), and at least one anchoring layer (2) applied to the wear layer, characterized in that the anchoring layer consists of a composition such that the ratios between the complex shear modulus at the temperature of 40 ° C and the complex shear modulus at the temperature of 100 ° C is greater than 50 (G * ₄ ° C / G * -ioo ° c> 50), and having a start cohesion increase at a temperature above 60 ° C.

8. A process for obtaining a carpet covering comprising a layer of tuft type fibers, called the wear layer (1), and at least one anchoring layer (2) applied to the wear layer, characterized in that it is implemented by having previously carried out the selection method according to any one of claims 1 to 6 to select the composition of the anchoring layer.

9. Production method according to claim 7 or 8, characterized in that the anchoring layer (2) is applied by coating via a roller coater or a doctor blade application, preferably at a temperature of 180 ° C. .

10. Use of the composition selected by the method according to any one of claims 1 to 6, for the manufacture of carpet, in particular of carpet tiles as removable lead slabs.