JP4573028B2 - Dust control mat - Google Patents

Description

In the present invention, a backing adhesive mainly composed of a carboxyl group- modified acrylonitrile butadiene latex is applied to the back surface of a tufted pile fabric and subjected to sealing treatment, and then acrylonitrile butadiene rubber is used as a main material. The present invention relates to a dust control mat in which an unvulcanized rubber base mat is superposed on a sealing treatment surface of a tufted pile fabric, and is heated under pressure to vulcanize the unvulcanized rubber base mat.

  Dust control mats are placed at the entrances and exits of passageways and are used to remove mud and dust adhering to footwear, many of which are handled as rental mats by leasers and frequently washed under harsh conditions. (See, for example, Patent Document 1).

As such, if washing frequently under harsh conditions, there will be a partial expansion and contraction difference in the dust control mat, which will appear in the entire dust control mat as wrinkle-like rippling, losing the commercial value as a rental mat. Therefore, it must be discarded (for example, see Patent Document 2). As a method of avoiding the wrinkle, there is a method in which a crosslinking agent is blended in the backing adhesive used for the sealing treatment, and the crosslinking treatment of the backing adhesive is performed simultaneously with the heat vulcanization treatment of the unvulcanized rubber base sheet. As the cross-linking agent, urea melamine resin, phenol resin, epoxy resin, imine, amine, polyvalent metal oxide, polyvalent metal salt (hydroxide) is used (for example, Patent Document 3). reference).
Japanese Patent No. 3297667 Japanese Patent No. 2726665 Japanese Patent No. 2615092

  In the prior art, the wrinkle generated in the dust control mat is not completely eliminated. Therefore, in order to investigate the cause of the wavy wrinkles generated in the dust control mat, in particular, when washing, moisture is transferred from the pile surface of the tufted pile fabric which is the surface material of the dust control mat to the back stitch (pile yarn) on the back surface of the base fabric. Each time it is washed, the fibers that make up the back stitch are repeatedly swollen and dried, and a slight amount of stretch distortion of the fibers that accompanies the swelling and drying is accumulated, which gradually becomes the rippling of the entire dust control mat. It was thought to be due to appearing.

  Therefore, based on this assumption, the inventors obtained a knowledge that a polyisocyanate that is cross-linked by moisture is blended with the backing adhesive and subjected to a sealing treatment to avoid wrinkles that occur in the dust control mat. Furthermore, if the polyisocyanate is blocked so that it does not react with moisture at room temperature, the backing adhesive used for the sealing treatment can be stored for a long period of time, and the backing adhesive remaining after the sealing treatment is air. It was found that it can be stored and reused without being reactively cured by touching the water inside.

The dust control mat according to the present invention has been completed by obtaining such knowledge, and has an adhesive for backing which contains a blocked polyisocyanate mainly composed of carboxyl group- modified acrylonitrile-butadiene latex on the back surface of the tufted pile fabric. After applying an adhesive and applying a sealing treatment, an unvulcanized rubber base mat mainly composed of acrylonitrile, butadiene, and rubber is placed on the sealing surface of the tufted pile fabric, and heated to apply pressure. made by vulcanizing a vulcanized rubber base mat, unreacted polyisocyanate is the first feature that you have remained in the adhesive for the backing.

  The second feature of the dust control mat according to the present invention is that the tufted pile fabric is formed by planting a pile mainly made of nylon on a base fabric.

  A third feature of the dust control mat according to the present invention is that the tufted pile fabric is formed by planting a pile mainly composed of acrylic fibers on a base fabric.

  Blocked polyisocyanates do not react with moisture at room temperature. Therefore, the viscosity of the backing adhesive used for the sealing treatment is stably maintained until it is applied to the back surface of the tufted pile fabric and heated. Therefore, when applied to the back surface of the tufted pile fabric, there is no excess or deficiency in the coating amount of the backing adhesive and no coating spots occur, and the backing adhesive is applied evenly. Pile fibers constituting the back stitch are coated with the backing adhesive, and then the polyisocyanate dissociated from the blocked polyisocyanate reacts with moisture. The backing adhesive is solidified to form a sealing layer.

  When using the dust control mat or washing, even if moisture permeates from the pile surface to the back of the base fabric and the back stitch absorbs moisture, it remains in the backing adhesive that forms the sealing layer. The unreacted polyisocyanate reacts with moisture, so that the pile fibers that make up the back stitch are not hygroscopically swollen by the moisture that permeates. It does not occur between the base mat and the wrinkle of the dust control mat due to the difference in expansion and contraction is avoided.

  Therefore, the present invention is effective for a dust control mat in which a pile is composed of hygroscopic fibers such as nylon, acrylic fiber, rayon, cotton fiber, and vinylon that absorb moisture and promote a dust capturing function. Since the blocked polyisocyanate does not react until it is heated even when it is exposed to moisture, the viscosity of the backing adhesive is stably maintained in the coating process performed at room temperature, and therefore the backing adhesive during the sealing process. Is easy to handle, can effectively perform the sealing process of tufted pile fabric, and can save and reuse the backing adhesive remaining after the sealing process. The cost of the dust control mat can be reduced and the industrial advantage of the present invention is great.

  The “blocked polyisocyanate” referred to in the present invention means a polyisocyanate whose reaction with moisture at room temperature is blocked by a blocking agent. Examples of the polyisocyanate include diisocyanate polymers such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate, isocyanurate ring-containing polymers, and urethane prepolymer compounds. As the blocking agent, oxime compounds such as monoalkylphenol, dialkylphenol, acetylacetone, acetoacetate ester, oxybenzoic acid ester, acetooxime, methylethylketoxime, methylisobutylketoxime, and the like are applied.

A polyester fiber nonwoven fabric having a basis weight of 120 gf / m ² is used as a base fabric, a nylon crimped multifilament yarn having a single yarn fineness of 21 dtex and a total fineness of 2600 dtex is used as a pile yarn, a needle gauge of 3.97 mm (5/32 cm), a stitch gauge of 2. On the back of a tufted pile fabric having a length of 54 mm (1/10 mm), a pile length of 11 mm, and a pile basis weight of 1000 gf / m ² , 222.2 parts by weight of a carboxyl group-modified acrylonitrile butadiene latex (45 wt% solid content) 11.4 parts by weight of isocyanate (solid content 44% by weight), 0.2 parts by weight of antifoaming agent (silicone), 3.0 parts by weight of thickener (sodium polyacrylate), and anti-aging agent (phenolic) ) 0.8 parts by weight comprising a backing adhesive 180gf / m ² (dry weight) was applied, 10 min at 0.99 ° C. It was carried out sealing treatment by heating and drying. The blocked polyisocyanate was composed of 35 parts by weight of isocyanate, 4 parts by weight of an emulsifier, 5 parts by weight of methyl ethyl ketoxime, and 56 parts by weight of water.

100 parts by weight of acrylonitrile butadiene rubber, 2 parts by weight of vulcanizing agent (sulfur), 5 parts by weight of zinc oxide, 2.5 parts by weight of vulcanization accelerator, 4.5 parts by weight of anti-aging agent, and plasticizer 40 An unvulcanized rubber base mat (thickness 1.2 mm, size 89 cm × 77 cm) composed of 12 parts by weight, reinforcing agent (silicon oxide) 12 parts by weight, and carbon black 60 parts by weight is subjected to the above-mentioned sealing treatment. The tufted pile fabric was superposed on the back surface, pressurized at a pressure of 4 kg / m ² , vulcanized for 12 minutes while maintaining the heating temperature at 150 ° C., and a dust control mat with a periphery surrounded by a rubber base mat was obtained.

[Comparative Example]
On the back of the tufted pile fabric used in the examples, 222.2 parts by weight of a carboxyl group-modified acrylonitrile butadiene latex (solid content 45% by weight), 2.0 parts by weight of a crosslinking agent (zinc white), and an antifoaming agent ( 120 gf / m of a backing adhesive composed of 0.2 parts by weight of silicone), 1.4 parts by weight of a thickener (sodium polyacrylate), and 0.8 parts by weight of an antioxidant (phenolic). ^{2 After} applying (dry weight), heat-drying at 150 ° C. for 10 minutes and performing a sealing treatment, the unvulcanized rubber base mat used in the example was overlaid on the back of the tufted pile fabric. Was vulcanized in the same manner as above to obtain a dust control mat with a periphery surrounded by a rubber base mat.

[Washing durability test]
The dust control mats of the example and the comparative example are put into a rotating drum having a diameter of 80 cm and a depth of 40 cm together with 1 liter of water (60 ° C.) and 300 g of detergent, and the drum is intermittently changed for 5 minutes while changing the direction of forward and reverse rotation every minute. Rotate and pre-treat, then change the forward / reverse rotation direction every minute as in the pre-treatment, rotate intermittently for 15 minutes, remove the cleaning liquid, replace the water, and change the drum rotation direction forward / reverse every minute Change and rotate intermittently for 5 minutes, replace the dirty water with new water, change the forward and reverse rotation direction every minute again, rotate intermittently for 5 minutes, dehydrate and dry at 80-90 ° C for 30 minutes The washing test was conducted 10 times, and the presence or absence of wavy wrinkles was visually inspected.
In the dust control mat of the example, no generation of wavy wrinkles was observed, and in the dust control mat of the comparative example, generation of wavy wrinkles was recognized.

Claims (3)

The back side of the tufted pile fabric was coated with a backing adhesive containing a blocked polyisocyanate containing carboxyl- modified acrylonitrile butadiene latex as the main material, and then treated with acrylonitrile butadiene rubber. The unvulcanized rubber base mat used as a material is superimposed on the sealing treatment surface of the tufted pile fabric, and is heated under pressure to vulcanize the unvulcanized rubber base mat, which is unreacted with the backing adhesive. dust control mat polyisocyanate and said that you have left.   The dust control mat according to claim 1, wherein the tufted pile fabric is formed by implanting a pile mainly composed of nylon on a base fabric.   The dust control mat according to claim 1, wherein the tufted pile fabric is formed by planting a pile mainly composed of acrylic fibers on a base fabric.