JP3356873B2 - Method for producing polyurethane backing material for carpet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a carpet backing material comprising a polyurethane-based elastic material and a reinforcing layer such as a nonwoven fabric. By bonding the carpet material to the carpet backing material obtained by the production method of the present invention,
A carpet excellent in durability, cushioning property, and the like can be obtained.

[0002]

2. Description of the Related Art It is already known to use as a backing material for carpets a chip made of a flexible polyurethane foam as industrial waste or scrap and integrally bonded by a urethane-based binder. For example, Japanese Utility Model Publication No. 2-1106 discloses that a mixture obtained by adding a filler such as fiber waste to a soft foam into chips by crushing or the like is combined with a binder to form a sheet, and a nonwoven fabric is formed on one surface thereof. And the like. A backing layer provided with such a cloth is disclosed. As a manufacturing method, a cloth is adhered to a mixture of a chip and a binder, and the whole body is compressed and cured to a desired thickness, and the binder is reacted and hardened by adding water vapor. It is stated that the backing layer is completed. Further, it is described that as a reaction hardening means of the binder, an aqueous solution to which a catalyst has been added in advance can be sprayed on the material in a stage before the compression, and the material can be reactively hardened by heat compression. In addition, a thick urethane chip assembly is manufactured in a mold, sliced to the required thickness,
A method is also known in which a nonwoven fabric or the like is bonded to one surface with an adhesive, and a carpet material is bonded to the other surface.

[0003] However, in the technique disclosed in Japanese Utility Model Publication No. 2-1106, the bonding strength between the chips is not sufficient even if the binder is reacted and hardened by any means. Is inferior in durability. Also, in the above method, the surface of the urethane chips integrated with the bonding material is considerably rough, and the adhesive strength between the cloth to be disposed on one side and the carpet ground bonded to the other side and the chip bonded body is sufficient. Rather, the resulting carpet also has poor durability and the like, like the backing layer. Furthermore, in the method of slicing the urethane chip assembly manufactured in the mold, since the accuracy of the thickness in the slicing process capability is at most about ± 0.7 to 1.0 mm,
A carpet having a large variation in thickness, for example, when used as a tile carpet, is inconvenient because it may be stumbling even though it has a step of only about 1 mm.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and recycles a flexible polyurethane foam which is an industrial waste, is inexpensive, and has excellent durability and thickness accuracy. It is an object of the present invention to provide a method for producing a polyurethane-based backing material for automobiles.

[0005]

SUMMARY OF THE INVENTION The method for producing a polyurethane-based backing material for carpets according to the present invention comprises a soft polyurethane foam.
Raw material mainly composed of urethane chips obtained by crushing foam
And a urethane-based binder, and then mix the
And then introduce heated steam into the formulation
To solidify the binder, react the urethane chips
The raw material used as the main material is reduced by the binder solidified by the reaction.
To obtain a urethane-based conjugate bound to the body,
Sliced to constant thickness and the sliced urethane bond
A reinforcing layer is laminated on one side of the body,
0.2-3.0 kg / cm ² force , time 0.5 minutes or more
In some cases, the combined body may have a thickness of 20 to 70% of the predetermined thickness.
And heat-fixed. Ma
Production of polyurethane backing material for carpet of the present invention
In the method, the breaking strength according to the following measuring method of carpet polyurethane backing is not less 0.5 kg / 25 mm or more, that the thickness accuracy of the backing is to be less than the predetermined thickness of ± 0.5 mm I can . Measuring method: A carpet material is joined to a surface of the elastic body where the reinforcing layer is not joined under conditions that do not cause interfacial destruction and cohesive destruction of the adhesive. A peeling test with the carpet material is performed. 180 degree peel test, pulling speed: 20 cm / min Also, in the present invention, the breaking strength is 1.0 kg / 25 mm.
, And the can be made the thickness precision is less than or equal to a predetermined thickness ± 0.3 mm or more.

As the above-mentioned "flexible polyurethane foam", foam treated as industrial waste or scrap can be used without any particular limitation as long as the performance as a backing material for carpet is not adversely affected. The method of “crushing” is not particularly limited, and “urethane chips” obtained by crushing are also used.
Any shape may be used, and usually an irregular shape can be used as it is without any processing, but if the uniform distribution of the chips in the backing material or the bonding force between the chips by the bonding material is taken into consideration, , Most of which have a major axis of 3 to 10 mm
It is preferable that the number of chips is in the range of the order, and the chips that are too fine or coarse are not included as much as possible.

The above-mentioned "urethane-based binder" is formed by bonding and solidifying a raw material mainly composed of urethane chips with a "urethane-based binder". As the above-mentioned "raw material", in addition to urethane chips as a "main material", fiber waste and the like can be appropriately used in combination as a filler. If the used carpet is used, for example, by crushing used carpet, waste of synthetic resin such as polyvinyl chloride used as a backup layer will be mixed in addition to fiber waste. There is no particular problem as long as the performance of the backing material is not reduced. The ratio of the components other than the main material to the total amount of the raw materials is preferably up to about half, but the ratio can be further increased by, for example, increasing the amount of the binder. The shape and size of the filler may be the same as those of the urethane chip.

Further, the above-mentioned "urethane-based binder" may be an ordinary urethane stock solution, for example, a product obtained by partially adding toluene diisocyanate to triol, or a product obtained by mixing triol or a diol thereof with toluene diisocyanate or diphenylmethane. What added diisocyanate etc. can be used. When the binder is solidified by the reaction, the urethane chip and the filler are integrally bonded to each other to form a urethane-based composite. The thickness of the bonded body is not particularly limited, and the target thickness of the “polyurethane-based elastic body” or “polyurethane-based backing material” obtained by compressing the bonded body or by pressing and heat-fixing the bonded body. What is necessary is just to determine it taking into consideration.

As the "reinforcing layer", use of a nonwoven fabric made of polypropylene fiber, polyester fiber or the like is preferable in terms of economy, but other woven fabrics and synthetic resin films can also be used. When peeling off from the floor, it is possible to use a material having a tensile strength, tear strength, or the like that cannot withstand the adhesive force between the carpet and the floor and that does not break and partially remain on the floor. . Considering the solvent used in the adhesive during carpet construction, the dissipation of moisture, etc. to the outside, and the permeability between the carpet and floor after construction, etc. Is more preferred.

The method for producing a polyurethane-based backing material for carpets of the present invention comprises, as described above , mixing a urethane-based binder with a raw material mainly composed of urethane chips obtained by crushing a flexible polyurethane foam, The mixture is filled into a mold, and then heated steam is introduced into the mixture to cause the binder to react and solidify. The raw material mainly composed of the urethane chips is integrated by the binder that has been reacted and solidified. And then slicing the urethane-based composite to a predetermined thickness, laminating a reinforcing layer on one side of the sliced urethane-based composite, at a temperature of 150 to 230 ° C. and a pressure of 0.2 to 3 Under the conditions of 0.0 kg / cm ² and the time of 0.5 minutes or more, the combined body is pressed to a thickness of 20 to 70% of the predetermined thickness and thermally fixed.

As a method of mixing a urethane-based binder into a raw material, for example, a urethane chip is put into an appropriate blender, and while the binder is dry-blended, the binder is blown into the blender by a spray gun or the like, and the mixture is sufficiently stirred. For mixing as uniformly as possible. In addition, when using an extender, if the urethane chips and the extender are uniformly mixed before being charged into the blender, the urethane chips, the extender and the binder can be more uniformly mixed. It is preferable. This mixture is filled in a mold, and the binder is reacted and solidified by, for example, introducing heated steam to form a urethane-based binder.

The "pressing" and "thermal fixing" are performed under the predetermined temperature, pressure and time. If the temperature is lower than 150 ° C., the heat fixation becomes insufficient and the breaking strength of the polyurethane-based elastic body decreases, and if the temperature exceeds 230 ° C., the urethane chip may be thermally degraded. Pressure is 0.2kg / cm
^If it is less than ² , a backing material having a predetermined uniform thickness cannot be obtained, and if it exceeds 3.0 kg / cm ² , no further effect is obtained and it is useless. On the other hand, if the time is less than 0.5 minute, the heat setting becomes insufficient. It is sufficient that this time is about 10 minutes, especially about 5 minutes or less. If the temperature is in the range of 160 to 200 ° C., the pressure is in the range of 1.0 to 2.0 kg / cm ² and the time is in the range of 2 to 3 minutes, a polyurethane-based backing material having better thickness accuracy and breaking strength can be obtained. preferable.

By the above steps, the elastic body, including the reinforcing layer laminated on one surface thereof, is compressed to a thickness of 20 to 70% of the thickness of the combined body to form the backing material of the present invention. If the compression ratio is less than 20%, sufficient thickness accuracy and breaking strength cannot be obtained, and if the compression ratio exceeds 70%, the backing material becomes too hard, and the cushioning properties and the like of the obtained carpet deteriorate. This compression ratio is particularly preferably about 40 to 60%, and within this range, a backing material or a carpet having excellent performance can be obtained. Further, the thickness of the obtained backing material is 2 to 10 mm in consideration of the physical properties such as hardness and elasticity of the elastic body and the performance as a carpet, for example, heat insulation and heat insulation, floor impact sound insulation, and feeling of bottoming. In particular, the range of 3 to 6 mm is preferable.
Furthermore, in the present invention, even when the thickness of the backing material is as thick as 10 mm, the backing material can have high thickness accuracy.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. Example 1 110 kg of a chip 4 made of a flexible polyurethane foam crushed to a length of about 3 to 10 mm was prepared. Separately from this, a urethane-based binder 5 (existing in a urethane-based binder) obtained by polyadding toluene diisocyanate to a soft urethane foaming polypropylene glycol having a molecular weight of 2,500 to 3,500, and appropriately diluting with a solvent three-fold. 15 kg of the binder was prepared by reacting and solidifying the binder, but the same number is used for convenience.). Thereafter, the entire amount of the chip 4 was put into a blender, and the binder 5 was blown into the entire chip 4 as uniformly as possible with a spray gun while dry blending, and the mixture was sufficiently stirred. Next, the stirred mixture was filled into a metal mold having an inner dimension of 1 m each in the vertical and horizontal directions and a depth of 80 cm. Thereafter, heated steam was introduced into the mold, and the binder 5 was reacted and solidified to obtain a urethane-based binder.

The combined body obtained as described above has a thickness of 8 mm.
, And a nonwoven fabric 6 made of black polyester fiber (trade name “Axter”, product weight: 30 g / m ² , manufactured by Toray Industries, Inc.) is laminated on one surface thereof. Between the hot plates set at 180 ° C. and pressurized to gradually narrow the space between the hot plates, and to make the gap between the hot plates 4 m
m and heat-fixed at 1.5 kg / cm ² for 2.5 minutes. Thereafter, the mixture is cooled to room temperature while being pressed between the hot plates, and the polyurethane-based backing material 2 comprising the obtained polyurethane-based elastic body 3 and the non-woven fabric 6 is bonded to the surface of the non-woven fabric 6 where the non-woven fabric 6 is not bonded. The carpet material 1 was bonded with an agent (manufactured by Inoac Co., Ltd., trade name "135KTS") to obtain a carpet composed of a backing material and a carpet material.

EXAMPLE 2 Instead of 110 kg of a chip made of a flexible polyurethane foam, 50 kg of a chip made of used carpet crushed to the same shape and size as the chip of 60 kg (20 kg of fiber waste, polyvinyl chloride as a backup material) A backing material and a carpet were obtained in the same manner as in Example 1 except that the waste material (30 kg) was used and the urethane binder was increased to 20 kg. Comparative Example 1 4 mm from the urethane-based composite as an intermediate product of Example 1
The sheet having a thickness was sliced, and a nonwoven fabric was bonded to one surface of the sheet and a carpet material was bonded to the other surface by a urethane-based adhesive without heat fixing to obtain a carpet.

The thickness accuracy of the backing material obtained in Examples 1 and 2 and Comparative Example 1 and the density and breaking strength of the polyurethane-based elastic material were measured (in the peeling test between the carpet material and the backing material, The peeling test was used as a measuring method, but the breaking strength was used as a physical property because the elastic body was broken rather than the interface peeling between the material and the adhesive and the cohesive failure of the adhesive itself.) Each test method is as follows. Thickness accuracy: Measured with a mylocometer. Density: Measure the weight (kg) of a cube with a side of 10 cm,
Expressed as a value obtained by dividing weight by volume. Breaking strength: 180 ° peel test, specimen width: 25 mm, tensile speed: 20 cm / min.

[0018]

[Table 1]

According to the results shown in Table 1, the density of each of the examples in which the pressing and the heat fixing were performed was greatly increased as compared with the density of the comparative example in which the heat fixing was not performed. In each embodiment, the accuracy is four times higher than that of the comparative example, and even when used like a tile carpet, the entire surface can be made a smooth surface with almost no steps. Further, the breaking strength of the elastic body was twice or more in Example 1 and three times or more in Example 2 as compared with the comparative example, and it is understood that the backing material of the present invention has a large strength. In the present invention, the present invention is not limited to the specific examples described above,
Various embodiments can be made within the scope of the present invention depending on the application.

[0020]

According to the present invention, a backing material for a carpet is obtained by using as a raw material even a flexible foam or a waste carpet treated as industrial waste or scrap. Therefore, it also helps to solve the problem of waste disposal, and an inexpensive backing material or carpet can be obtained. In addition, the thickness accuracy is greatly improved as compared with conventional products, and the breaking strength is extremely large, so that the resulting carpet has excellent durability, cushioning properties, and the like. Further, the backing material of the present invention has more excellent thickness accuracy and breaking strength. Further, in the present invention, the conventional backing material manufacturing process is improved by a simple manufacturing process in which a heat-fixing process is added by pressing a polyurethane-based elastic body by using a compression molding machine or the like. A backing material with high performance can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a carpet in which a carpet material is bonded to a polyurethane-based backing material of Example 1.

[Explanation of symbols]

1; carpet material; 2; polyurethane-based backing material; 3; polyurethane-based elastic material; 4; urethane chip; 5; urethane-based binder; 6;

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-93357 (JP, A) JP-A-3-120735 (JP, U) JP-A-58-147482 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) A47G 27/02

Claims (3)

(57) [Claims] 1. A crushed flexible polyurethane foam.
Urethane chips are used as raw materials mainly made of urethane chips.
The ingredients are then compounded, then the compound is filled into the formwork and then
Then, the above-mentioned binder is introduced by introducing heated steam into the above-mentioned composition.
The reaction is solidified and the raw material is mainly made of the urethane chips.
Are bonded together by the above-mentioned binder solidified by the reaction.
Urethane-based composite, and then slide it to the specified thickness.
And reinforce one side of the sliced urethane-based composite
The layers are laminated, the temperature is 150-230 ° C., the pressure is 0.2-3.
0 kg / cm ² , time 0.5 minute or more
When the body is pressed to a thickness of 20 to 70% of the predetermined thickness,
Polyurethane for carpet, which is heat-fixed
A method for manufacturing a tongue-based backing material. 2. A polyurethane backing material for the carpet.
Has a breaking strength of 0.5 kg / 25 m according to the following measurement method.
m or more, and the polyurethane backing material for carpet
2. The thickness accuracy of a predetermined thickness is ± 0.5 mm or less.
A method for producing a polyurethane-based backing material for carpet according to the above. Measurement method: Surface of the elastic body where the reinforcing layer is not bonded
In the conditions under which interfacial failure and cohesive failure of the adhesive do not occur,
-Join the pet ground and use a 25 mm wide specimen to
A peeling test between the backing material and the carpet material is performed. 180 degree peel test, tensile speed: 20 cm / min 3. The breaking strength is 1.0 kg / 25 mm or less.
The thickness accuracy is above the specified thickness ± 0.3mm
3. The polyurethane backing material for carpet according to claim 2, wherein
Manufacturing method.