JPH11291434A - Urethane foam with adhesive and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide urethane foam with adhesive which is free of creasing and curling and has high dimensional accuracy. SOLUTION: Urethane foam 10 with adhesive has polyurethane foam 11, a plastic film 12 reaction-bonded at least to one surface side of the polyurethane foam 11, 10-50 μm thick and constituted of rigid plastic having an elastic modulus of 10000 kg/cm<2> or above and a melting point of 150 deg.C or above, an adhesive layer 13 provided on the plastic film 12 and a release liner 14 laminated on the adhesive layer 13 and 70-200 μm thick.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane foam with a pressure-sensitive adhesive suitable for use as, for example, a sealing material, a cushioning material or a soundproofing material, and a method for producing the same.

[0002]

2. Description of the Related Art A so-called double-sided tape is used as a means for fixing a urethane foam to a surface to be stuck to various devices or the like. In other words, a double-sided tape with paper is laminated on urethane foam in advance, and when the urethane foam is fixed to the mating surface of the various devices, the paper is peeled off and the adhesive of the double-sided tape is adhered to the mating surface. I stick it.

[0003] However, double-sided tapes have problems such as the need to apply an adhesive on both the front and back surfaces of a thin base material, the production is relatively troublesome, and the cost is high. Also,
When reattaching after construction or removing after use, the adhesive of the double-sided tape sometimes remained on the mating surface.

[0004]

Accordingly, the present applicant has proposed a pressure-sensitive adhesive foam sheet disclosed in Japanese Patent Application Laid-Open No. 58-173179. This product was made by foaming a foam on a non-liquid-permeable intermediate film coated with an adhesive. However, the foamed product was wrinkled and curled (curved). Therefore, it is difficult to apply to precision equipment and electronic equipment that require dimensional accuracy.

Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive urethane foam which can provide an adhesive layer on a polyurethane foam without using a double-sided tape, can prevent wrinkles and curls, and has improved dimensional accuracy, and a method for producing the same. To provide

[0006]

A urethane foam with a pressure-sensitive adhesive according to the present invention for achieving the above object is provided on at least one of the front and back surfaces of the polyurethane foam and has a thickness of 10 μm to 5 μm.
0 μm, elastic modulus 10,000 kg / cm ² or more and melting point 1
A plastic film made of a rigid plastic of 50 ° C. or more, an adhesive layer applied to the plastic film, and a thickness of 70 μm to 200 μm laminated on the adhesive layer
μm release liner, wherein the polyurethane foam is reactively bonded to the plastic film.

According to the present invention, the plastic film includes one made of polypropylene or polyethylene terephthalate. The present invention also includes a release liner in which both front and back surfaces are subjected to a plastic coating treatment. Further, the plastic coating of the release liner may be of a polypropylene type.

The production method of the present invention has a thickness of 10 μm to 5 μm.
0 μm, elastic modulus 10,000 kg / cm ² or more and melting point 1
Producing a single-sided adhesive tape by supplying an adhesive layer between a plastic film made of a rigid plastic of 50 ° C. or more and a release liner having a thickness of 70 μm to 200 μm, and urethane on the other side of the plastic film Supplying the undiluted solution, foaming, reacting and bonding the foamed urethane to the plastic film, and curing at a temperature of 120 ° C. or less to obtain a polyurethane foam.

The thickness of the plastic film is 10 μm.
Exceeding the range of m-50μm or elasticity 10,000kg
If the melting point is less than / cm ² or the melting point is less than 150 ° C., the resulting urethane foam with an adhesive may be wrinkled or curled, and the object of the present invention cannot be achieved. Furthermore, the thickness of the release liner is 70 μm to 200 μm.
Even if it deviates from the range of m, wrinkles and curls occur, and the object of the present invention could not be achieved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the urethane foam 10 with an adhesive of this embodiment
Is a polyurethane foam 11, a plastic film 12 provided on at least one of the front and back surfaces of the polyurethane foam 11, a plastic film 12
And a release liner 14 laminated so as to cover the entire surface of the pressure-sensitive adhesive layer 13. FIG. 1 shows a state in which a part of the release liner 14 has been peeled off from the adhesive layer 13.

The plastic film 12 has a melting point of 1 so as to withstand the curing temperature of the polyurethane foam 11.
50 ° C. or higher, thickness 10 μm to 50 μm, elastic modulus 1000
A highly rigid plastic (rigid plastic) of 0 kg / cm ² or more is used. As a preferred example of the rigid plastic, a resin mainly composed of polypropylene or polyethylene terephthalate is recommended, and polyethylene terephthalate is particularly preferred in terms of heat resistance and rigidity.

The plastic film 12 is formed by reacting and adhering to the polyurethane foam 11 at the time of foam molding of the polyurethane foam 11, which will be described later, and may be subjected to a corona discharge treatment in order to enhance the adhesion with the polyurethane foam 11, Alternatively, a film for improving the adhesiveness may be laminated on the plastic film 12, or a surface treatment with a well-known primer may be performed.

The plastic film 12 has a higher heat-resistant temperature, a higher rigidity, and a larger thickness in order to make the urethane foam 10 with the adhesive less likely to curl. In other words, considering that the urethane foam 11 with the pressure-sensitive adhesive is adhered while being bent at a corner or the like, the workability of a material that is too hard deteriorates. Therefore, the thickness (10
(μm to 50 μm) and a plastic film 12 having an elastic modulus in the range.

For the pressure-sensitive adhesive layer 13, a well-known rubber-based or synthetic resin-based pressure-sensitive adhesive is used. For example, an acrylic adhesive obtained by polymerizing an acrylate monomer, a urethane adhesive, an SBS (styrene butadiene styrene) adhesive, or the like is used. These pressure-sensitive adhesives are applied to the plastic film 12 as a solvent system, an aqueous system, a solventless reaction type liquid system, a hot melt system, or the like. The thickness of the pressure-sensitive adhesive layer 13 is suitably from 10 μm to 2000 μm.

The release liner 14 is formed of a paper or a synthetic resin film such as polyethylene terephthalate or the like, and at least one surface thereof is provided with a scriber (plastic coating) such as a silicone resin. . Examples of the lysing agent include polypropylene, polyethylene, polymethylpentene, and fluororesin. The coating thickness of the lysing agent is about 0.1 μm to 40 μm. The thickness of the entire release liner 14 is preferably 70 μm to 200 μm. Within this thickness range, the production stability of the polyurethane foam 11 is good, such as curling can be suppressed and the dimensional accuracy can be improved without particularly deteriorating the thermal conductivity when the polyurethane foam 11 is foam-molded. .

The release liner 14 is coated with a polypropylene film or a polymethylpentene film on the substrate as the squeezing process, so that the release liner 14 itself curls even when exposed to a high temperature during foaming or curing. The dimensional accuracy after foaming of the polyurethane foam 11 is further improved. Then, by performing a silicone resin treatment or a fluororesin treatment on the silicate treatment agent, the releasability can be adjusted. As a more preferred embodiment, by performing the above-described squeezing treatment on both the front and back surfaces of the release liner 14, the release liner 14 does not curl when exposed to a high temperature, and the dimensional accuracy after foaming is further improved.

The polyurethane foam 11 has a shrinkage ratio (a reduction ratio of a dimension after curing to a dimension immediately after foaming).
Is preferably controlled to be 3.0% or less. The shrinkage of a polyurethane foam varies with various factors. For example, it depends on the temperature at the time of foaming, the curing temperature, the curing time, and the like, including the types and parts of polyol and isocyanate, which are raw materials of polyurethane, the number of parts of water as a foaming agent, and the number of parts of an auxiliary foaming agent. The shrinkage rate (shrinkage rate of polyurethane foam) in this specification means a reduction rate (change rate) of a dimension after curing with respect to a dimension immediately after foaming.

In this embodiment, in order to reduce the shrinkage of the polyurethane foam 11 to 3.0% or less, the temperature at the time of foaming the polyurethane foam 11 is set to 30 ° C. to 90 ° C.
Curing temperature is 120 ° C. or less, more preferably 100 ° C.
It is good to be below ° C.

The thickness of the polyurethane foam 11 is preferably in the range from 0.1 mm to 50 mm. Thickness 5
If the thickness exceeds 0 mm, not only is it difficult to mold with the current urethane foam production equipment, but also the shrinkage force of the polyurethane foam 11 is less than that of the plastic film 1.
2 and the bending strength of the release liner 14, which causes curl. If the thickness of the polyurethane foam 11 is less than 0.1 mm, it is difficult to exhibit commercial properties as a sealing material, a vibration-proof material, and a sound-proof material in the current market.

The urethane foam with the adhesive 1
0 will be described. As shown in FIG. 3, the pressure-sensitive adhesive 13a is supplied to one surface of the release liner 14, is thinly spread, and is dried.
To form Further, by laminating the plastic film 12 on the pressure-sensitive adhesive layer 13, a single-sided pressure-sensitive adhesive tape 15 protected by a release liner 14 is produced. In addition, after supplying the adhesive 13a on the plastic film 12, the single-sided adhesive tape 15 may be manufactured by laminating the release liner 14 on the adhesive 13a.

Next, as shown in FIG. 4, with the release liner 14 of the single-sided adhesive tape 15 facing downward, a polyurethane solution 11a is applied to the other surface of the plastic film 12 by a coating device 20 to a predetermined thickness. Apply to. The coating apparatus 20 includes a knife coater 21
In other words, any known spray coater or roll coater may be used as long as the urethane stock solution 11a can be applied thinly and uniformly.

After applying the urethane stock solution 11a, foaming is completed at room temperature to 90 ° C., and curing is performed at the above temperature (120 ° C. or lower) in an oven at room temperature to high temperature. The cured polyurethane foam 11 attempts to shrink at a shrinkage rate of 3% or less compared to the dimension immediately after foaming.
Due to the rigidity of 4, the apparent shrinkage of the polyurethane foam 11 is suppressed, and the generation of wrinkles and curls is effectively avoided.

The urethane stock solution 11a is applied to the coating apparatus 20.
By applying a single-sided adhesive tape 15 to both sides of the polyurethane foam 11 when applying to a predetermined thickness, the single-sided adhesive tape 15 is provided on both sides of the polyurethane foam 11 as shown in FIG. May be produced.

Alternatively, as shown in a urethane foam with adhesive 10B shown in FIG.
The polyurethane foam 11 is foamed in a state where the one-sided pressure-sensitive adhesive tape 15 is provided on one surface and a release liner 25 made of ordinary paper or film is provided on the other surface, and the release liner 25 is peeled off after curing. It may be. Further, the one-sided adhesive tape 15 is provided on one side of the polyurethane foam 11, and the polyurethane foam 1
The skin layer may be formed on the surface by foaming the other surface without providing anything. [Example] A single-sided pressure-sensitive adhesive tape was constituted by a 13-μm-thick polyethylene terephthalate film, a 50-μm-thick acrylic pressure-sensitive adhesive coated on one side thereof, and a release liner covering the pressure-sensitive adhesive. By applying a polyurethane foam stock solution on a 100 μm thick paper (laminated with polypropylene on paper) having a total thickness of 100 μm provided on the lower surface side, a thickness of 10 mm and a density of 0.
A polyurethane foam with a pressure-sensitive adhesive tape of 05 g / cm ² was produced. The temperature at the time of foaming was about 70 ° C., and the temperature after foaming was 120 ° C. for 7 minutes. The shrinkage of the polyurethane foam was 2.9%, and the configuration of the release liner used was as shown in Examples 1, 2, and 3 in Table 1.

[0025]

[Table 1] Comparative Example 1 A urethane foam with an adhesive was produced in the same manner as in Example 1 except that the thickness of the release liner for a single-sided adhesive tape in Example 1 was changed to 30 μm. Although this foam did not have wrinkles, it was impossible to judge comprehensively, such as remarkable curl and poor dimensional accuracy. [Comparative Example 2] A urethane with an adhesive was prepared in the same manner as in Example 1 except that a polypropylene-polyethylene copolymer film (thickness: 145 ° C) (thickness: 20 µm) was used instead of the polyethylene terephthalate film in Example 1. A foam was made. This foam had wrinkles in the pressure-sensitive adhesive layer and had poor dimensional accuracy.

[0026]

According to the urethane foam with the pressure-sensitive adhesive according to the first aspect, wrinkles and curls do not occur after foaming, and a product having high dimensional accuracy can be obtained. Further, since the plastic film and the polyurethane foam are integrated with each other by reactive bonding, an adhesive such as a double-sided tape for bonding the two can be omitted.

In a conventional urethane foam with an adhesive using a double-sided tape, the adhesive may peel off from the polyurethane foam and remain on the mating surface when reattached after construction or removed after use. However, according to the present invention, since the pressure-sensitive adhesive is securely fixed to the polyurethane foam via the plastic film, there is no problem that the pressure-sensitive adhesive remains on the surface to be bonded even when peeled off from the surface to be bonded. .

According to the second aspect of the invention, by using polypropylene or polyethylene terephthalate for the plastic film, curling and wrinkling can be more effectively suppressed.

According to the third aspect of the present invention, since the release liner is provided with a plastic coating on both sides, the release liner itself does not curl even when exposed to high heat during foaming or curing of the polyurethane foam. In addition, curling and wrinkling of the urethane foam product with an adhesive can be more effectively suppressed, and a product having high shape accuracy can be obtained.

According to the fourth aspect of the invention, the use of a polypropylene-based plastic coating for the release liner makes it possible to more effectively suppress the occurrence of curling and wrinkling, and to provide a urethane with an adhesive with high shape accuracy. A foam product is obtained.

According to the manufacturing method of the fifth aspect, the process is simplified as compared with a conventional polyurethane foam to which a double-sided adhesive tape is attached, wrinkles and curls are not generated, and a product having high dimensional accuracy can be obtained. can get. Further, an adhesive for bonding the plastic film and the polyurethane foam can be omitted.

A polyurethane foam having poor adhesion;
For example, polyurethane foam containing polybutene, asphalt, organophosphorus flame retardant, etc. was difficult to attach double-sided adhesive tape, so conventionally it required a complicated process such as primer treatment, but the urethane foam with adhesive of the present invention is Since the plastic film and the polyurethane foam are integrated by reactive adhesion, they can be securely adhered to each other without performing a primer treatment, and there is no problem in adhesion.

[Brief description of the drawings]

FIG. 1 is a perspective view of a part of a urethane foam with an adhesive according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a part of the urethane foam with an adhesive shown in FIG.

FIG. 3 is a cross-sectional view conceptually showing equipment for forming an adhesive layer of the urethane foam with an adhesive.

FIG. 4 is a cross-sectional view conceptually showing equipment for molding the polyurethane foam of the urethane foam with an adhesive.

FIG. 5 is a cross-sectional view of a urethane foam with an adhesive showing another embodiment of the present invention.

[Explanation of symbols]

 10, 10A, 10B ... urethane foam with adhesive 11 ... polyurethane foam 12 ... plastic film 13 ... adhesive layer 14 ... release liner

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G10K 11/162 C09K 3/10 R 11/16 D // C09K 3/10 Z G10K 11/16 A D

Claims (5)

[Claims] 1. A plastic film comprising a polyurethane foam and a rigid plastic provided on at least one of the front and back surfaces of the polyurethane foam, having a thickness of 10 μm to 50 μm, an elastic modulus of 10,000 kg / cm ² or more and a melting point of 150 ° C. or more. And a pressure-sensitive adhesive layer coated on the plastic film, and a release liner having a thickness of 70 μm to 200 μm laminated on the pressure-sensitive adhesive layer, wherein the polyurethane foam is reactively bonded to the plastic film. Urethane foam with adhesive. 2. The urethane foam with an adhesive according to claim 1, wherein said plastic film is made of polypropylene or polyethylene terephthalate. 3. The urethane foam with an adhesive according to claim 1, wherein a plastic coating is applied to both front and back surfaces of the release liner. 4. The urethane foam with an adhesive according to claim 3, wherein the plastic coating of the release liner is made of polypropylene. 5. An elastic modulus of 100 μm and a thickness of 10 μm to 50 μm.
A plastic film made of a rigid plastic having a melting point of not less than 00 kg / cm ² and a melting point of not less than 150 ° C.
a single-sided pressure-sensitive adhesive tape by supplying a pressure-sensitive adhesive layer between the resin film and a release liner having a thickness of 200 to 200 μm; supplying a urethane stock solution to the other side of the plastic film to foam the foamed urethane; Obtaining a polyurethane foam by reacting and adhering to a film and curing at a temperature of 120 ° C. or lower.