JP2023072864A - floor mat - Google Patents

Abstract

To provide a floor mat which has a high coefficient of static friction in initial testing, can suppress lowering of the coefficient of static friction after repetition tests, and shows less appearance change before and after usage.SOLUTION: A floor mat has a foam layer containing a thermoplastic resin as a main component and microcapsules on one surface of a fibrous sheet support, and has a protective layer containing a thermoplastic resin as a main component on the foam layer.SELECTED DRAWING: None

Description

The present invention relates to floor mats (eg, automotive floor mats).

In conventional automobile floor mats, spike nibs made of resin are provided on the rear surface of the floor mat in order to increase the frictional force with the vehicle floor material (Patent Document 1), and fiber ends are melted (Patent Document 2, 3) and providing a non-adhesive viscoelastic layer containing foamed microcapsules (Patent Document 4).

There is a demand for the development of floor mats that exhibit a higher anti-slip effect, but up until now, slip load evaluations have been conducted based on the average value of N=5 at the maximum, assuming only new products. rice field.

Japanese Patent No. 6430311 Japanese Utility Model Laid-Open No. 60-36784 Japanese Patent No. 4072916 JP-A-11-105176

The present inventors provided a foam layer containing foamed microcapsules on one surface of a fiber-based support, and further provided a protective layer on the foam layer, thereby improving the coefficient of static friction during the initial test. Also, it was found that the decrease in the coefficient of static friction after repeated tests can be suppressed.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a floor mat having a high coefficient of static friction in the initial test. Another object of the present invention is to provide a floor mat capable of suppressing a decrease in static friction coefficient after repeated tests. Further, another object of the present invention is to provide a floor mat which is free from whitening and has little change in appearance before and after use.

The above problems can be solved by the following inventions:
[1] On one surface of a fibrous sheet support, a foam layer containing a thermoplastic resin as a main component and containing foamed microcapsules is provided, and a protective layer comprising a thermoplastic resin as a main component is provided on the foam layer. floor mats.
[2] The foam layer contains 0.6 to 12 parts by weight of foamed microcapsules with respect to 100 parts by weight of the thermoplastic resin, and the protective layer contains 0 to 12 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The floor mat of [1], comprising the foamed microcapsules of
[3] The foam layer contains 0.6 to 3 parts by weight of foamed microcapsules with respect to 100 parts by weight of the thermoplastic resin, and the protective layer contains 0.4 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The floor mat of [2], containing parts by weight of foamed microcapsules.

Since the floor mat of [1] of the present invention has a protective layer on the foam layer, it has a higher coefficient of static friction in the initial test than a floor mat without a protective layer.
The floor mat of [2], which is a preferred embodiment of the present invention, can suppress a decrease in static friction coefficient after repeated tests.
The floor mat of [3], which is another preferred embodiment of the present invention, shows no whitening and little change in appearance before and after use.

In the floor mat of the present invention, a foam layer containing foamed microcapsules is provided on one surface of a fibrous sheet support, and a protective layer is provided on the foam layer.

The fibrous sheet support in the floor mat of the present invention may itself be the surface carpet base material, or a surface layer carpet base material may be separately prepared to combine the fibrous sheet support and the surface carpet base material, for example. , an adhesive, fusion, or the like. Examples of the fibrous sheet support include nonwoven fabrics such as spunbond nonwoven fabrics and needle-punched nonwoven fabrics, woven fabrics, knitted fabrics, films, and the like. As the carpet substrate, conventionally known carpet mat sheets can be used, and examples thereof include tufted carpet, needle punch carpet, hook carpet, and woven fabric base fabric made of natural fibers or synthetic fibers.

Both the foam layer and the protective layer are mainly resin layers, and the foam layer contains foam microcapsules as an essential component, but the protective layer may or may not contain foam microcapsules. In the present specification, the term "mainly composed of resin" means that the content of resin constituting the foam layer or protective layer is typically 80% or more, preferably 90% or more, and more preferably 95%. % or more, more preferably 98% or more.

As the resin layer, the type of thermoplastic resin may be a general-purpose one, for example, an acrylic resin containing structural units derived from (meth)acrylic acid and/or (meth)acrylic acid ester; vinyl acetate-based resin containing a structural unit; vinyl chloride-based resin containing a structural unit derived from vinyl chloride; butadiene-styrene-based, butadiene-acrylonitrile-based, chloroprene-based synthetic rubber-based resin; etc. are preferred. These resins can be used alone or in combination of two or more. Among them, a butadiene-styrene synthetic rubber resin is preferable because of its excellent initial adhesiveness.
The glass transition temperature of the thermoplastic resin is preferably -30 to 50°C, more preferably -20 to 40°C.

The foamed microcapsules are not limited to the following, but for example, thermally expandable microcapsules are mixed with the resin constituting the resin layer, and after coating on one surface of the fibrous sheet support, Heat-drying expands the thermally expandable microcapsules in the resin, forming a foamed layer and a protective layer containing the foamed microcapsules.
Examples of thermally expandable microcapsules that can be used in the present invention include microcapsules having a configuration in which a vaporizable liquid is encapsulated in a thermoplastic polymer such as vinylidene chloride or acrylonitrile. In the thermally expandable microcapsules, the thermoplastic polymer constituting the outer shell is softened by heating, and at the same time, the volatile liquid contained therein is gasified to increase the internal pressure and expand. This state is sometimes referred to as an internal hollow resin capsule. As the vaporizable liquid, a liquid that is liquid at room temperature and vaporizes at the expansion start temperature can be appropriately used, and hydrocarbons are preferable.

The average median particle size of the thermally expandable microcapsules in an unexpanded state is 20 µm or more, more preferably 25 µm or more, still more preferably 30 µm or more, and 70 µm or less, more preferably 65 µm or less, and still more preferably 60 µm. It is below.
The average median particle size of the thermally expandable microcapsules can be measured, for example, with a laser diffraction particle size distribution analyzer ("SALD-2300" manufactured by Shimadzu Corporation).
The expansion start temperature of the thermally expandable microcapsules is preferably 70° C. or higher, more preferably 90° C. or higher, and still more preferably 100° C. or higher. Also, the maximum expansion temperature of the thermally expandable microcapsules is preferably 200° C. or lower, more preferably 180° C. or lower, and still more preferably 165° C. or lower.

The foam layer and protective layer can optionally contain, for example, antifoaming agents, pigments, thickeners, etc., in addition to the resin and foamed microcapsules.

The content ratio of the foamed microcapsules contained in the foam layer and the protective layer can be appropriately determined within the range in which the effects of the present invention can be obtained. The protective layer may contain 0.6 to 12 parts of foamed microcapsules per 100 parts of thermoplastic resin. Within this range, the coefficient of static friction during the initial test is high, and a decrease in the coefficient of static friction after the repeated test can be suppressed.
In addition, the protective layer containing 0 to 12 parts of foamed microcapsules with respect to 100 parts of the thermoplastic resin means that the protective layer does not contain foamed microcapsules, or the protective layer exceeds 0 parts and 12 parts. It is meant to contain foamed microcapsules of:

The content ratio of the foamed microcapsules contained in the foam layer and the protective layer is that the foam layer contains 0.6 to 3 parts of foamed microcapsules per 100 parts of the thermoplastic resin, and the protective layer contains 0.6 to 3 parts of the thermoplastic resin. It preferably contains 0.4 to 3 parts of foamed microcapsules per 100 parts. Within this range, the coefficient of static friction during the initial test is high, the decrease in coefficient of static friction after repeated tests can be suppressed, and the foam layer and protective layer turn white when the floor mat is pulled horizontally. There is no discoloration (whitening), and there is little change in appearance before and after use.

When the content of foamed microcapsules in the foam layer is the same as or slightly higher than the content of foamed microcapsules in the protective layer, for example, when the foam layer is 3 parts, the protective layer is 2 to 3 parts; 3 to 6 parts in the protective layer when 6 parts in the layer; 0.6 to 1.2 parts in the foam layer and 0.4 to 0.6 parts in the protective layer after 20 tests It is more preferable because the decrease in the coefficient of static friction can be suppressed to 40% or less.

The amount of the foam layer to be applied to the fibrous sheet support can be determined as appropriate within the ^range in which the effects of the present invention can be obtained. ^m2 .
The coating amount of the protective layer on the fibrous sheet support can be appropriately determined within the ^range in which the effects of the present invention can be obtained. 40 g/ ^m2 .

The automobile floor mat of the present invention is not limited to the following, but for example, a coating liquid to be a foam layer (foaming layer coating liquid) and a coating liquid to be a protective layer (protective layer coating liquid). is prepared, and a predetermined amount of the foam layer coating liquid is applied to one surface of a separately prepared fibrous sheet support using an appropriate means (for example, a knife coater), and dried by heating (for example, at 120 ° C. for 1 minute) to form a foam layer, then a predetermined amount of the protective layer coating solution is applied to the surface of the foam layer using a suitable means (e.g., knife coater), and dried by heating (e.g., , 140° C. for 1 minute) to form a protective layer, thereby manufacturing the automobile floor mat of the present invention.
The same coating liquid may be used for the coating liquid for the foam layer and the coating liquid for the protective layer, or two types of coating liquids that differ in the presence or absence or content of the resin layer or thermally expandable microcapsules may be used. may

In this specification, the static friction coefficient (μS) of the floor mat can be measured according to the measurement method according to JIS P 8147:2010 "7 horizontal method". Specific conditions can be implemented based on Test Example 1 described later.

EXAMPLES The present invention will be specifically described below with reference to Examples, but these are not intended to limit the scope of the present invention.

<<Production Example 1: Preparation of floor mat base material>>
A polyester heat-embossed spunbond nonwoven fabric (basis weight: 100 g/m ² ) was prepared as a fibrous sheet support.
On the other hand, a polyester spunbond primary base fabric (basis weight: 100 g/m ² ) was tufted with a polypropylene pile using a 1/8G tufting machine, and then filled with a styrene-butadiene emulsion (glass transition temperature: -10°C). By doing so, a tufted carpet (pile basis weight: 600 g/m ² , filling material amount: 240 g/m ² ) was prepared.

<<Production Example 2: Preparation of coating liquid>>
1. Preparation of coating solution A (expanded microcapsule content 3 parts)
SBR latex (solid content 48%, Smartex (registered trademark) NSA302H, manufactured by Nippon A&L Co., Ltd.) 100 parts, antifoaming agent (solid content 15.6%, Formrex (registered trademark) S-90, Nicca Chemical Co., Ltd.) 0.2 parts, black pigment (solid content 30%, RYUDYE (registered trademark)-W BLACK RCP, manufactured by DIC Corporation) 2 parts, thermally expandable microcapsules (solid content 98%, Matsumoto Microsphere (registered trademark) FN-78D, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) was added and mixed.
Next, a thickener (solid content: 25%, D-251, manufactured by GOO CHEMICAL INDUSTRY CO., LTD.) was added to the mixture while mixing, and the viscosity was adjusted to 6000 cps to prepare a coating liquid A.
Coating liquid A contains 3 parts of thermally expandable microcapsules per 100 parts of SBR latex in terms of solid content.

2. Preparation of coating solution B (expanded microcapsule content 6 parts) (Solid content 98%) A coating solution B was prepared by repeating the steps of Production Example 2-1 except for adding 3 parts.
Coating liquid B contains 6 parts of thermally expandable microcapsules with respect to 100 parts of SBR latex in terms of solid content.

3. Preparation of Coating Solution C (Expanded Microcapsule Content: 12 Parts) (Solid content 98%) A coating liquid C was prepared by repeating the steps of Production Example 2-1 except for adding 6 parts.
Coating liquid C contains 12 parts of thermally expandable microcapsules per 100 parts of SBR latex in terms of solid content.

4. Preparation of coating solution D (expanded microcapsule content: 0.6 parts) A coating solution D was prepared by repeating the steps of Production Example 2-1, except that 0.3 parts of microcapsules (solid content 98%) was added.
Coating liquid D contains 0.6 parts of thermally expandable microcapsules per 100 parts of SBR latex in terms of solid content.

5. Preparation of coating solution E (expanded microcapsule content: 1.2 parts) A coating solution E was prepared by repeating the steps of Production Example 2-1, except that 0.6 parts of microcapsules (solid content 98%) was added.
Coating liquid E contains 1.2 parts of thermally expandable microcapsules per 100 parts of SBR latex in terms of solid content.

6. Preparation of Coating Liquids F to K Instead of adding 1.5 parts of thermally expandable microcapsules (solid content of 98%) to 100 parts of SBR latex (solid content of 48%), thermally expandable microcapsules (solid content of 98%) were added. %) except for adding 0.2 parts, 0.4 parts, 0.5 parts, 1 part, 2 parts, 4 parts, by repeating the steps of Production Example 2-1, respectively, coating liquid F (0.4 parts), coating liquid G (0.8 parts), coating liquid H (1 part), coating liquid I (2 parts), coating liquid J (4 parts), coating liquid K (8 parts) prepared.

7. Preparation of coating solution Z (expanded microcapsule content 0 parts) A coating liquid Z was prepared by repeating the steps of Production Example 2-1, except that (solid content 98%) was not added.
The coating liquid Z does not contain thermally expandable microcapsules.

<<Production Example 3: Preparation of Floor Mat>>
On one surface of the heat-embossed spunbond nonwoven fabric prepared in Production Example 1, the various coating liquids prepared in Production Example 2 were applied in a dry coating amount (coating amount after drying) of 30 g / m ² with a knife coater. and dried at 120° C. for 1 minute to form a foamed layer containing foamed microcapsules.
Next, on the surface of the foam layer, various coating liquids prepared in Production Example 2 were coated with a knife coater so as to have a dry coating amount of 20 g/m ² and dried at 140°C for 1 minute to form a protective layer. formed.
170 g/m ² of molten olefin hot melt adhesive was applied to the back surface of the tufted carpet prepared in Production Example 1, and the non-coated surface of the heat-embossed spunbond nonwoven fabric coated with various coating liquids was used as the tufted carpet. The floor mat of the present invention was prepared by stacking the hot-melt adhesive on the surface coated with the hot-melt adhesive and pasting them together with a nip roll.

As a comparative example, one surface of a heat-embossed spunbond nonwoven fabric was coated with various coating liquids prepared in Production Example ² with a knife coater so that the dry coating amount was 50 g/m A floor mat for comparison was prepared in which only a foam layer was formed by drying for 1 minute.

<<Test Example 1: Effect of protective layer>>
The coefficient of static friction (μS) of the floor mat was calculated according to the measurement method according to JIS P 8147:2010 "7 horizontal method". Measurement was performed with a load of 7 kg, a test piece of 230×200 mm, and a contact surface of 200×200 mm, and the applied pressure was adjusted to 1.72 kPa (1.64 kPa±0.24 kPa, excluding the weight of the test piece).
As the base material, a cotton-blended nonwoven fabric shown in Table 1 (basis weight: 200±20 g/m ² , thickness: 2.5 mm, punch density: 250 punches/cm ² ) was used.

Table 2 shows the results.
As is clear from the comparison between Comparative Example 1 and Examples 1 and 2, and the comparison between Comparative Example 2 and Examples 3 and 4, the provision of the protective layer improved the coefficient of static friction.
Further, as is clear from the comparison between Example 1 and Example 2, or the comparison between Example 3 and Example 4, the protective layer does not contain foamed microcapsules (Examples 1 and 3). ,
No significant difference in the coefficient of static friction was observed between those containing (Example 2, Example 4).

<<Test Example 2: Examination of the content ratio of foamed microcapsules and effect on 20 times test>>
In this test example, the contents of the foamed microcapsules contained in the foam layer and the protective layer were changed as shown in Tables 3A to 3D, and the effects thereof were examined. If the content of the thermally expandable microcapsules in the coating liquid exceeds 12 parts per 100 parts of the SBR latex, the material will fall off from each layer when dried. part as the upper limit.
In addition, as Comparative Example 4, a floor mat provided with resin-made spike nibs (Patent Document 1) was prepared.

The results are shown in Tables 3A-3D. The names of the coating liquids are omitted, and only the weight parts of the thermally expandable microcapsules per 100 parts of the SBR latex are shown in terms of solid content.
In addition, the static friction coefficient shows the 20th measured value in addition to the first measured value, and is expressed by the following formula:
(Reduction rate) = [{(initial µS) - (20th µS)}/(initial µS)] x 100 (%)
was calculated.
In addition, as an index of changes in appearance before and after use, it was observed whether or not the foam layer and protective layer turned white (whitening) when the floor mat was pulled horizontally.

Regarding the initial coefficient of static friction, the foam layer containing no foamed microcapsules (Comparative Example 3) had a significantly lower value even though it had a protective layer.
In addition, none of Examples 1 to 17 (the content of foamed microcapsules is 0.6 to 12 parts in the foam layer and 0 to 12 parts in the protective layer) does not have a protective layer ( (See Comparative Examples 1 and 2 in Table 2), or showed a higher initial coefficient of static friction than the one with a spike nib made of resin (Comparative Example 4).
Furthermore, all of Examples 1 to 17 exhibited higher numerical values than Comparative Examples 3 and 4 with respect to the coefficient of static friction at the 20th test, that is, the coefficient of static friction after the 20th test.

Regarding whitening, Examples 2, 5, 6, and 14 to 17 (the content of foamed microcapsules is 0.6 to 3 parts in the foam layer and 0.4 to 0.4 parts in the protective layer). In part 3), whitening was not observed, and it was confirmed that there was little change in appearance before and after use.

Regarding the reduction rate, Examples 5 and 6 (when the content of foamed microcapsules is 3 parts in the foam layer, 2 to 3 parts in the protective layer), Examples 9 and 10 (the content of foamed microcapsules When the content rate is 6 parts in the foam layer, 3 to 6 parts in the protective layer), Examples 14 to 16 (the content rate of foamed microcapsules is 0.6 to 1.2 parts in the foam layer) , 0.4 parts to 0.6 parts in the protective layer), the reduction rate is 40% or less, and the content of foamed microcapsules in the foam layer is less than the content of foamed microcapsules in the protective layer. When the ratio was the same or slightly higher, the decrease in static friction coefficient in repeated tests was suppressed.

The present invention relates to floor mats (eg, automotive floor mats).

Claims (2)

A foam layer composed mainly of a thermoplastic resin and containing foamed microcapsules is provided on one surface of a fibrous sheet support, and a protective layer composed mainly of a thermoplastic resin is provided on the foam layer. floor mat. The foam layer contains 0.6 to 12 parts by weight of foamed microcapsules with respect to 100 parts by weight of thermoplastic resin, and the protective layer contains 0 to 12 parts by weight of foamed microcapsules with respect to 100 parts by weight of thermoplastic resin. 2. A floor mat according to claim 1, comprising capsules.