JP2856922B2 - Molded surface fastener and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded surface fastener having excellent flexibility, tearability and removability, and a method for producing the same.

[0002]

2. Description of the Related Art In the industries such as automobiles and home appliances, it has been practiced to assemble molded bodies by using screws or the like and to assemble molded bodies that have been specially processed. For the purpose of shortening, a double-sided adhesive or a hook-and-loop fastener is often used. For example, an automobile seat or the like has a structure in which a skin material is covered on a cushion body, but a seat surface may be depressed for maintaining a sitting posture or for decoration.

When such a seat is manufactured, a hook-and-loop fastener is attached to the back surface of the skin material in order to prevent the skin material from floating up from the cushion body in the recently depressed shape portion, and a molded surface fastener is also provided on the depressed shape portion. It has been studied to prevent the skin material from floating by using the foam molded body attached as a cushion body and engaging the engaging portions of the two surface fasteners.

[0004]

In addition to such uses,
Molded surface fasteners have been used in various applications, but molded surface fasteners made of conventional polyamide elastomers, polyolefins, polyester elastomers, etc., have good engaging properties but flexibility, and are inferior in repeated detachability,
As described above, there is a problem that it cannot be used in a portion having a complicated shape and repeatedly deforming.

Accordingly, it is an object of the present invention to provide a molded surface fastener excellent in flexibility, tearability and removability, and a method for producing the same.

[0006]

SUMMARY OF THE INVENTION The present invention is a flexible molded surface fastener comprising a specific thermoplastic polyurethane and a method for producing the same. That is, the present invention provides: (1) a polyurethane obtained by reacting a high molecular diol having a number average molecular weight of 500 to 3,000, a low molecular diol having a molecular weight of less than 500, and an organic diisocyanate, a. The ratio of nitrogen atoms in the polyurethane is 3.0 to 3.0.
6.0% by weight, and b. (2) a molded surface fastener made of a thermoplastic polyurethane having an intrinsic viscosity of 0.7 to 1.5 dl / g as measured with a dimethylformamide solution of a polyurethane at 30 ° C; and (2) a high-molecular diol having a number average molecular weight of 500 to 3000; A polyurethane obtained by reacting a low molecular weight diol having a molecular weight of less than 500 and an organic diisocyanate, comprising: a. The ratio of nitrogen atoms in the polyurethane is 3.0 to 3.0.
6.0% by weight, and b. A molded surface fastener comprising: extruding a thermoplastic polyurethane having an intrinsic viscosity of 0.7 to 1.5 dl / g as measured with a dimethylformamide solution of the polyurethane at 30 ° C. and, if necessary, stretching. It is intended to provide a manufacturing method.

[0007] In order to obtain an excellent molded surface fastener made of polyurethane, it is necessary to select an appropriate polyurethane composition and molecular weight. The thermoplastic polyurethane used for the molded surface fastener of the present invention is a polymer elastic body composed of a soft segment and a hard segment, and has a number average molecular weight of 500 to 3000, a high molecular weight diol, and a molecular weight of 50.
It is synthesized from a low molecular weight diol of less than 0 and an organic diisocyanate according to a conventional method. If the number average molecular weight of the high molecular diol is less than 500, the elastic properties of the molded surface fastener are undesirably reduced. On the other hand, when it exceeds 3,000, the flowability of the polyurethane at the time of melting becomes poor, and molding becomes difficult, and a molded surface fastener of stable quality cannot be obtained. When the molecular weight of the low molecular weight diol is 500 or more, the elastic property of the molded surface fastener is undesirably reduced.

In a polyurethane obtained by reacting a high molecular diol having a number average molecular weight of 500 to 3,000, a low molecular diol having a molecular weight of less than 500 and an organic diisocyanate, the weight percent of nitrogen atoms in the polyurethane (hereinafter referred to as N
%) Means that the proportion of the organic diisocyanate, which is a component having a nitrogen atom, among the components constituting the polyurethane, that is, the proportion of the hard segment, increases. In the present invention, when N% exceeds 6, the resin becomes hard, and it is not possible to ensure moldability and flexibility. On the other hand, if it is less than 3, it becomes too soft and the workability of the molded surface fastener is poor, and the engaging force of the obtained molded surface fastener is also small, so that sufficient performance as a surface fastener cannot be exhibited. The molecular weight of the polyurethane affects the moldability and the performance of the molded surface fastener. When the intrinsic viscosity [η] in a dimethylformamide solution at 30 ° C. is smaller than 0.7, a satisfactory molded surface fastener cannot be obtained due to insufficient viscosity, and the mechanical strength of the molded surface fastener is also reduced. Performance cannot be obtained. On the other hand, polyurethane having [η] of more than 1.5 has poor fluidity during molding, has poor extrudability, and causes surface roughness and the like, and it is difficult to obtain a good molded surface fastener.

The high molecular weight diol used in the present invention is a high molecular weight compound having two hydroxyl groups at the molecular chain terminals obtained by polycondensation, addition polymerization (for example, ring opening polymerization) or polyaddition. Examples include polyester diols, polyether diols, polycarbonate diols, and co-condensates thereof (for example, polyester
Ether diol). These may be used alone or as a mixture of two or more.

As the above polyester diol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methylpropanediol, 1,8-octanediol, 2-methyl-1,8
Alkanediols having 2 to 10 carbon atoms such as octanediol and 1,9-nonanediol or mixtures thereof and glutaric acid, adipic acid, azelaic acid, pimelic acid, speric acid, sebacic acid, terephthalic acid, isophthalic acid, etc. A saturated polyester diol obtained from an aliphatic or aromatic dicarboxylic acid having 4 to 12 carbon atoms or a mixture thereof, or a polylactone diol such as polycaprolactone glycol, polypropiolactone glycol, or polyvalerolactone glycol is preferably used. .

As the above-mentioned polyether diol, polyalkylene ether diols such as polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol and polyhexamethylene ether glycol are preferably used.

Further, the above-mentioned polycarbonate diols include those having 2 to 2 carbon atoms such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol. 12
And aliphatic or alicyclic diols or polycarbonate diols obtained by condensation polymerization of diphenyl carbonate or phosgene with a mixture thereof are preferably used.

The number average molecular weight of these high molecular weight diols is desirably in the range of 500 to 3000, usually 500 to 2500. If the number average molecular weight is too small, the compatibility with the organic diisocyanate is too good, and the elasticity of the resulting polyurethane becomes poor. On the other hand, if the number average molecular weight is too large, the compatibility with the organic diisocyanate deteriorates, mixing during the polymerization process does not work well, and a stable polyurethane such as formation of a gel-like lump cannot be obtained.

The molecular weight used in the present invention is 500
Less than low molecular weight diols, ethylene glycol,
Propylene glycol, 1,4-butanediol, 1,
5-pentanediol, 3-methylpentanediol,
Examples thereof include aliphatic, alicyclic or aromatic diols such as 1,6-hexanediol and 1,4-bis (β-hydroxyethoxy) benzene. These may be used alone or in combination of two or more.

The organic diisocyanate used in the present invention includes 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, and 2,2'-dimethyl-
4,4'-diphenylmethane diisocyanate, 1,3
-Or aromatics such as 1,4-bis (isocyanatomethyl) benzene, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate , Alicyclic or aliphatic diisocyanates. These organic diisocyanates may be used alone or in combination of two or more.

For the purpose of improving or increasing the heat resistance and weather resistance of the polyurethane, inorganic fillers such as calcium carbonate, talc, carbon black, titanium oxide, silica, clay, mica, metal fine powder, barium sulfate and magnesium carbonate are used. Agents or organic fillers can be incorporated. In addition to the above, a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant, a tackifier, an antistatic agent, a foaming agent, and the like can be added to the polyurethane.

Next, a method for manufacturing the molded surface fastener of the present invention will be described. The molded surface fastener of the present invention can be obtained by melt molding using the above polyurethane. Various known molding methods can be used as the melt molding method, and examples include extrusion molding and injection molding. Extrusion molding is particularly preferred. A typical example of the extrusion molding is, for example,
This is described in detail in, for example, Japanese Patent Publication No. 22768 and Japanese Patent Publication No. 53-22889. The outline of these drawings (Fig. 1
To FIG. 4).

FIG. 1 shows an outline of a production apparatus. Polyurethane is superheated and kneaded by an extruder 1 and the melt is supplied to a continuous profile extrusion die 2. The molded body 3 extruded from the extrusion die 2 is cooled by a cooling sizing device 7 to form a rib support 5 and a rib head 6 which are continuous in the longitudinal direction of a sheet-like base member 4 as shown in FIG. I do.

The thus obtained continuous heteromorphic raw material 3
Is guided by a support roll 8, and as shown in FIG. 3, a cutting blade 10 of a cutting machine 9 performs a cutting process 11 in the longitudinal direction of the rib support 5 and the rib head 6, thereby forming a discontinuous rib 6 '. The cut body 3 ′ is sent to the constant-length roll 12 before stretching and is stretched between the constant-length roll 14 after stretching and the stretching tank 1.
3, it is generally stretched 1.5 to 3.5 times in the longitudinal direction,
As shown in the perspective view of Fig. 4, there is provided an engaging molded surface fastener 3 "having ribs 6 'spaced apart from the stretched base portion 4'. The molded surface fastener 3" may be formed as required. Post-processing such as heat setting and coating is performed.

[0020]

EXAMPLES Examples of the present invention will be shown below to explain the present invention more specifically and in detail, but the content of the present invention is not limited to these examples. In addition, the performance evaluation of the molded surface fastener was based on the following method.

A) Flexibility The value of the initial Young's modulus obtained by measuring mechanical properties by a method according to JIS K-7113, and JIS K-72.
The hardness value obtained by a method based on No. 15 was used as an index of flexibility. b) Tearability The tear strength of the base material of the molded surface fastener was measured by a method according to JIS K-6301-9.2, and this was used as an index of tearability. c) Repeated detachability Two pile base fabrics with a specific configuration and two molded surface fasteners
An operation of engaging by pressing with a roll having a roll load of kg (according to JIS L3416) and an operation of peeling off the engaged two times are repeated 10 times. And evaluated according to the following criteria. Peeling strength retention evaluation 60% or more Good (〇) 59-40% Slightly poor (△) 39% or less Poor (×)

Examples 1 to 6 Molded surface fasteners were produced using the polyurethane pellet compounds shown in Table 1 and the following method using the apparatus shown in FIG. First, using a single screw extruder having a diameter of 40 mm (full flight screw, L / D = 24), cylinder temperature 160 to 200 ° C., deformed die temperature 190 to 200 ° C.,
Extrusion amount 4 kg / Hr, profile extrusion speed 2.5 m / mi
The mixture was extruded under the conditions of n, and a raw shaped body was formed at a cooling water temperature of 25 ° C. Next, in the cutting step, the rib portion is cut into a pitch of 0.4 mm, stretched 2.5 times at a stretching temperature of 120 ° C., and heat-set at a line speed of 6 m / min to form a molded surface fastener having the shape shown in FIG. I got

The dimensions of each part of the molded surface fastener were as follows. The performance of the obtained molded surface fastener was evaluated, and the results are shown in Table 1. The quality of workability in these processing steps is
The flowability of the molten polymer to the details of the nozzle when extruded from the deformed nozzle and the uniform stretchability in the stretching step were visually determined.

Comparative Examples 1 to 6 Molded surface fasteners were manufactured in substantially the same manner as in Examples 1 to 6 except that the polyurethane used was the resin composition shown in Table 1, and the performance thereof was evaluated. It is shown in Table 3.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

In Table 1, the abbreviations in the columns of high molecular diol, low molecular diol and organic diisocyanate, which are polyurethane raw materials, mean the following compounds, respectively. PBA: polybutylene adipate diol PNOA: poly (nonamethylene / 2-methyloctane) adipate diol PCL: polycaprolactone diol 1,4-BD: 1,4-butanediol BHEB: 1,4-bis (β-hydroxyethoxy) benzene MDI: 4,4'-diphenylmethane diisocyanate

[0029]

The molded surface fastener of the present invention has flexibility,
It has the feature of being excellent in tearability and repetitive desorption properties. Particularly, the improvement of the flexibility and the improvement of the tearability of the molded surface fastener obtained by the production method of stretching the base material portion are remarkable. In addition, when manufacturing the molded surface fastener of the present invention, the moldability such as extrudability and stretchability is good, and the production process can be stabilized and speeded up, and the production cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view of a manufacturing apparatus for manufacturing a molded surface fastener of the present invention.

FIG. 2 is a partial perspective view of a continuous deformed raw material sheet.

FIG. 3 is a side view illustrating a cutting step.

FIG. 4 is a perspective view of a molded surface fastener.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Extrusion apparatus, 2 Profile extrusion die, 3 Continuously shaped raw material, 3 ′ cut-in processed product, 3 ″ molded surface fastener molded product, 4 base material portion, 4 ′ stretched base material portion, 5
Rib support, 6 rib head, 6 'discontinuous rib, 7 cooling sizing device, 8 support roll, 9 cutting machine, 10
Cutting blade, 11 notch processing line, 12 constant length roll before stretching, 13 stretching tank, 14 constant length roll after stretching.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-336001 (JP, A) Japanese Utility Model Application Sho 62-169608 (JP, U) Japanese Utility Model Application Utility Model Sho 62-203609 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) A44B 18/00 C08G 18/65 C08L 75/04

Claims (2)

(57) [Claims] 1. A polyurethane obtained by reacting a high molecular diol having a number average molecular weight of 500 to 3,000, a low molecular diol having a molecular weight of less than 500, and an organic diisocyanate, comprising: a. The ratio of nitrogen atoms in the polyurethane is 3.0 to 3.0.
6.0% by weight, and b. A molded surface fastener comprising a thermoplastic polyurethane having an intrinsic viscosity of 0.7 to 1.5 dl / g as measured in a dimethylformamide solution of the polyurethane at 30 ° C. 2. A polyurethane obtained by reacting a high molecular diol having a number average molecular weight of 500 to 3,000, a low molecular diol having a molecular weight of less than 500, and an organic diisocyanate, comprising: a. The ratio of nitrogen atoms in the polyurethane is 3.0 to 3.0.
6.0% by weight, and b. A molded surface fastener, comprising: extruding a thermoplastic polyurethane having an intrinsic viscosity of 0.7 to 1.5 dl / g as measured with a dimethylformamide solution of polyurethane at 30 ° C. and, if necessary, stretching. Production method.