JP2003034010A - Damping sheet - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To pulverize a PET film without peeling it from the damping resin layer, mix it with the damping resin layer again and supply it to the damping sheet, based on high raw material efficiency. Provide an inexpensive vibration damping sheet. SOLUTION: A vibration damping resin layer comprising a resin composition containing a styrene-isoprene block copolymer, an ethylene-vinyl acetate copolymer, an inorganic powder and a recycled polyethylene terephthalate powder and a polyethylene terephthalate film are laminated. Become a damping sheet.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-damping sheet suitable for use as a steel plate or the like and which can be provided at a low cost. [0002] Conventionally, various types of vibration damping sheets containing a thermoplastic resin or elastomer and an inorganic powder have been proposed. For example, Japanese Patent Application Laid-Open No. 3-28765
No. 1 discloses a vibration damping sheet comprising a vibration damping resin layer containing a styrene-isoprene block copolymer and an inorganic powder, which is obtained by laminating the composite material and a steel sheet. When shaping the damping material into a folded plate roof using roll forming, etc., the slip surface of the composite material on the contact surface of the forming die or the contact surface with the forming roll is insufficient. There is a problem that it is difficult to carry out the forming process and abrasion is caused on the obtained folded-plate roof or the like. For this reason, Japanese Patent Application Laid-Open No. Hei 10-183808 discloses that one surface of a vibration damping sheet comprising a vibration damping resin layer containing a styrene-isoprene block copolymer and an inorganic powder is coated with polyethylene terephthalate (PET). A laminated vibration damping material in which films are laminated has been proposed, and PE
It can be said that the problem of Japanese Patent Application Laid-Open No. 3-287661 has been solved because the T film imparts surface slipperiness. [0004] On the other hand, JP-A-3-28
No. 7651 and JP-A-10-18380
Regarding the industrial production method and productivity of the laminated vibration damping material described in Japanese Patent Publication No. 8, the vibration damping sheet of the former is a defective product in the middle of production (ear end, thickness defect, poor appearance, trouble stop loss, etc.).
However, since it was composed of a vibration-damping resin layer, it could be used as a raw material if it was put into a kneader again and melted. That is, it was possible to reduce material loss. However, in the latter laminated vibration damping material, a PET film is laminated on a vibration damping sheet. The melting temperature of the vibration damping sheet is about 100 ° C., whereas PET is 260 ° C. In terms of thermal efficiency, when processing a defective product in the course of manufacture, it is necessary to peel the PET and then feed it into the kneader. Therefore, the number of steps for removing the PET film is increased, and the peeled PET film becomes a waste, which causes a new problem in the industrial manufacturing method. The inventor of the present invention has found a problem in the method of manufacturing a laminated vibration damping material described in Japanese Patent Application Laid-Open No. Hei 10-183808 in the course of intensive studies to improve the productivity of the above-mentioned conventional vibration damping sheet. The present invention has been completed. That is,
SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive damping system based on high raw material efficiency, which can pulverize a PET film without peeling it from the damping resin layer, mix the PET film again with the damping resin layer, and supply it to the damping sheet. To provide a vibration sheet. In order to achieve the above object, the present invention provides a styrene-isoprene block copolymer, an ethylene-vinyl acetate copolymer, an inorganic powder and a recycled polyethylene terephthalate powder. Provided is a vibration damping sheet in which a vibration damping resin layer made of a resin composition and a polyethylene terephthalate film are laminated. Less than,
The present invention will be described in more detail. [0008] The styrene-isoprene block copolymer used in the vibration-damping resin layer is a block copolymer of styrene as a first component and isoprene as a second component, wherein butadiene is used in combination with isoprene. Is also good. Further, the second styrene-isoprene block copolymer
When the component is composed of isoprene alone or a mixture with butadiene, the content of the 3.4 component and the 1.2 component of the block component of the second component is preferably 40% or more.
If the content of the 3.4 bond and the 1.2 bond is less than 40%, the obtained vibration damping sheet may not exhibit sufficient vibration damping performance in a normal operating temperature range. The molecular weight of the styrene-isoprene block copolymer is preferably from 30,000 to 300,000, more preferably from 80,000 to 250,000. If the molecular weight is less than 30,000, mechanical properties such as strength at break and elongation of the block copolymer itself may be reduced. On the other hand, when the molecular weight exceeds 300,000, it becomes difficult to mix with an inorganic powder described later. Commercial products of such a styrene-isoprene block copolymer include, for example, "HIBLER" manufactured by Kuraray Co., Ltd. The ethylene-vinyl acetate copolymer used in the vibration damping resin layer preferably has a vinyl acetate content of 2 to 45% by weight. Vinyl acetate content of 2% by weight
If the amount is less than the above, the flexibility of the obtained damping sheet may be insufficient. If the amount exceeds 45% by weight, the resin composition has an adhesive property, and a special release treatment is required at the time of forming or storing the damping sheet. It may be. The recycled polyethylene terephthalate (PET) powder used for the vibration-damping resin layer is usually obtained by mechanically pulverizing a used PET in the form of a film, and has a size less than the thickness of the vibration-damping resin layer. And specifically,
0.5 mm or less. Since the processing temperature of the vibration damping resin layer is generally set to 150 ° C. or lower, the melting temperature is set to 260 ° C.
° C PET disperses without melting. When the vibration damping sheet is pulverized, it is not necessary to peel off the vibration damping resin layer and the PET film. After the pulverization, the vibration damping resin layer and the PET film are adhered to each other. Since a force is applied, the PET film is separated and dispersed. In a dispersed state, it plays the same role as the following inorganic powder. Since the above-mentioned recycled PET powder is basically obtained from the recovered material, the content in the vibration-damping resin layer is usually 5%.
% By weight or less, and preferably 1% by weight. Further, the ratio does not need to be always constant, and the input ratio of the collected material may be changed. Examples of the inorganic powder used in the vibration damping resin layer include metal oxides such as iron oxide, titanium oxide and magnesium oxide, particulate metals, clay, talc, mica, and the like.
In addition to crushed minerals such as quartz powder, glass fiber, glass powder,
Examples include calcium carbonate and gypsum. Among these,
In particular, mica and calcium carbonate are preferred from the viewpoint of vibration damping characteristics and cost. The particle size of the inorganic powder is not particularly limited, but is preferably 1 to 500 µm. If the particle size is less than 1 μm, the surface area increases and the number of particles per unit weight increases, so that the mixing step takes time. In addition, the particle size is 50
If the thickness exceeds 0 μm, the surface of the vibration damping sheet may be roughened or the sheet may be broken during molding. Preferred examples of the resin composition used for the vibration-damping resin layer include, for example, 20 to 5,000 parts by weight of an ethylene-vinyl acetate copolymer based on 100 parts by weight of a styrene-isoprene block copolymer. , PET powder 5-50
And those containing 200 to 10,000 parts by weight of inorganic powder. The blending amount of the ethylene-vinyl acetate copolymer is determined by the blending amount of the inorganic powder described below and the thickness and shape of the steel sheet used for lamination as necessary. May be reduced, and if it is increased, the vibration damping performance of the styrene-isoprene block copolymer may be reduced. Therefore, 20 to 5,000 parts by weight based on 100 parts by weight of the styrene-isoprene block copolymer is used. Preferably, it is more preferably 100 to 1,000 parts by weight. In particular, when the content of the styrene-isoprene block copolymer in the resin composition is 1% by weight or less, the styrene-isoprene block copolymer 1
It is preferable to blend the ethylene-vinyl acetate copolymer in an amount of 1,000 parts by weight or more based on 00 parts by weight. When the compounding amount of the above inorganic powder is small, it is necessary to increase the thickness of the obtained vibration damping resin layer in order to exhibit a predetermined vibration damping performance. Since the strength of the styrene-isoprene block copolymer may be reduced, the amount is preferably 200 to 10,000 parts by weight, more preferably 500 to 3,000 parts by weight, based on 100 parts by weight of the styrene-isoprene block copolymer. When the amount of the inorganic powder exceeds 1,000 parts by weight, the styrene-
It is preferable to blend 200 parts by weight or more of ethylene-vinyl acetate with respect to 100 parts by weight of the isoprene block copolymer. The above resin composition may contain a heat stabilizer, a weather resistance improving material, a lubricant, a processing aid, a pigment, a colorant, and the like, if necessary. In particular, it is preferable to add a petroleum resin (C9 resin) in order to improve the adhesiveness of the damping sheet to the steel sheet and the fluidity during molding. The thickness of the vibration-damping resin layer is appropriately determined depending on the resin composition, vibration-damping performance and the like, but is usually preferably 10 mm or less, more preferably 2 mm or less. If the thickness exceeds 10 mm, breakage or peeling may occur when a laminated body in which the vibration damping sheet and the steel sheet are laminated is formed into a corrugated cross section. The thickness of the PET film is appropriately determined according to the molding conditions and required performance to be applied.
500 μm is preferable, and more preferably 15 to 100 μm
m. When the thickness of the PET film is less than 5 μm,
In addition to the difficulty in forming the PET film, when the PET film is bonded to a steel plate, the surface slippage during subsequent forming may be insufficient, or the PET film may be broken. On the other hand, if the thickness of the PET film exceeds 500 μm, a large amount of PET resin is required for the surface slipperiness, which is uneconomical. In addition, the rigidity of the PET film becomes too large, and after the lamination with the steel sheet. It may be an obstacle during molding. The vibration damping resin layer and the PET film are preferably laminated using an adhesive or a pressure-sensitive adhesive. The opposite surface of the PET film may be subjected to processing such as silicon release processing or embossed roughening processing as necessary. Embodiments of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 Styrene-isoprene block copolymer ("HIBLER" manufactured by Kuraray Co., Ltd., molecular weight: about 14)
10,000) 13% by weight, ethylene-vinyl acetate copolymer (vinyl acetate content 30% by weight) 13% by weight, C9 petroleum resin 13% by weight, calcium carbonate (average particle size 2 μm) 36% by weight, mica (100 mesh) Pass) A composition consisting of 25% by weight was kneaded with a Banbury mixer to prepare a damping resin composition A. The composition A is put between two top rolls of a calender roll, heated and rolled, inserted into a center roll and transferred to form a vibration damping resin layer, and a PET film is sandwiched between the center roll and the bottom roll. By heating and rolling, the damping resin layer and the PET film were laminated, and on the other hand, a damping sheet B was produced while slitting a predetermined width at the edge of the ear. (At this stage,
The vibration damping sheet B may be manufactured while the ear end is mechanically set so that the PET film is peeled off and slit. The thickness of the damping resin layer is 0.5 mm.
The thickness of the PET film obtained by applying the VA-based hot melt adhesive to the laminated surface and applying the silicone release agent to the opposite surface was 25 μm. Defective products of the vibration damping sheet at the time of thickness adjustment at the start of roll forming were appropriately cut and secured (note that, at this stage, the PET film at the time of thickness adjustment at the start of roll forming was also adjusted). Only defective products may be cut and secured as necessary.) Next, the defective end of the edge of the slit-shaped vibration-damping sheet and the defective vibration-damping sheet at the time of adjusting the thickness, which were generated during the production of the vibration-damping sheet B, were crushed by freezing into a 0.2 mm square. The vibration-damping resin composition A was charged and mixed to obtain a vibration-damping resin composition a (a rejected PET film alone was frozen and pulverized to obtain a regenerated PET powder. It does not matter). The input amount of the recycled PET powder was 0.5% by weight. Except for using the damping resin composition a,
The vibration-damping resin layer and the PET
The intended vibration damping sheet b of the present invention, on which the film was laminated, was produced. A regenerated product consisting of a defective product at the time of adjusting the thickness of the vibration-damping sheet b and the edge portion of the vibration-damping sheet b after the slit, which is generated at the time of manufacturing the vibration-damping sheet b, is freeze-crushed,
The recycled PET powder was charged into the vibration damping resin composition A and mixed to obtain a vibration damping resin composition, and a vibration damping sheet was produced in the same manner as described above. Table 1 shows the production efficiency and the like of the vibration damping sheet b. Theoretically, it is 100%, but it is 99% in consideration of the case where there is a portion consumed by a crusher or the like. (Comparative Example 1) A damping resin composition A was prepared in the same manner as in Example 1, and a damping sheet B was produced in the same manner as in Example 1 while slitting the end of the ear. However, in the subsequent production of the vibration-damping sheet, the PET of the edge part after the slit generated at the time of producing the vibration-damping sheet B and the defective product at the time of adjusting the thickness were used.
Did not reuse. Therefore, as shown in Table 1, the production efficiency was lower than that of Example 1. <Evaluation method> Damping sheet b obtained in Example 1
And about the damping sheet obtained in Comparative Example 1, the loss coefficient of the damping material obtained by laminating SPC steel sheets, and the molded product obtained by processing the damping material obtained by laminating soft vinyl chloride resin-coated steel sheets, The loss coefficient and noise level were measured by the following methods, and the results are shown in Table 1. (1) After applying a solvent-type chloroprene-based adhesive to one surface of an SPC steel plate (JIS G 3141) having a loss coefficient of 0.6 mm and drying it,
The opposite side of the PET film laminated surface of the vibration damping sheet was adhered to the adhesive applied surface to obtain a vibration damping material composed of a laminated body of the vibration damping sheet and the SPC steel sheet. 15mm × 25
For the test piece cut to 0 mm, JIS G 0602
The loss coefficient at a frequency of 500 Hz was measured by the central excitation method according to the above. (2) A solvent-type chloroprene-based adhesive is applied to the steel sheet side of a soft vinyl chloride resin-coated steel sheet having a noise level of 0.6 mm, dried, and then opposite to the PET film laminated surface of the vibration damping sheet on the adhesive applied surface. By sticking the sides, a vibration damping material composed of a laminate of a vibration damping sheet and a soft vinyl chloride resin-coated steel sheet was obtained. After shaping this damping material into the shape of the folded plate roof shown in FIG. 1, this folded plate roof was fixed with the damping sheet side as the lower side, and the rainfall of 100 mm / hour from above the soft vinyl chloride laminated steel sheet side The rain level was artificially rained, and the noise level at a position 3 m below the folded roof was measured by a sound level meter. [Table 1] The vibration damping sheet of the present invention is constituted as described above, and is a vibration damping resin layer comprising a resin composition containing a specific copolymer, an inorganic powder and a recycled polyethylene terephthalate powder. And polyethylene terephthalate film are laminated, so that the vibration damping resin layer has good vibration damping properties and the polyethylene terephthalate film has surface smoothness. Therefore, for example, when the vibration damping material obtained by laminating the vibration damping sheet and the steel sheet is formed into a folded plate roof or the like using roll forming or the like, the workability is good. As in the case of using a vibration damping material obtained by laminating a steel sheet and a composite material without a polyethylene terephthalate film as described in JP-A-228751, abrasion occurs on a folded plate roof or the like obtained by molding. And other problems do not occur. Also, since the vibration damping resin layer contains recycled polyethylene terephthalate powder, the PET film is pulverized without peeling from the vibration damping resin layer, mixed with the vibration damping resin layer again, and supplied to the vibration damping sheet. It is possible to provide an inexpensive vibration damping sheet based on high raw material efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view schematically showing a shape of a folded plate roof used for measuring a noise level in an embodiment.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 53/02 C08L 53/02 67/02 67/02 F16F 15/02 F16F 15/02 Q F term (Reference) 3J048 AA06 AC03 BD04 EA38 4F100 AA00B AA08B AC05B AK12B AK12J AK28B AK28J AK42A AK42B AK68B AL02B AL05B BA02 BA16 DE01B JH02 JK11 JL16B 4J002 BB06X BP01W CF06DE236 DE076 DE116 DE116 DE116

Claims (1)

Claims: 1. A styrene-isoprene block copolymer,
A vibration damping sheet comprising a vibration damping resin layer comprising a resin composition containing an ethylene-vinyl acetate copolymer, an inorganic powder and a recycled polyethylene terephthalate powder, and a polyethylene terephthalate film laminated.