JP4269384B2 - Olefin resin foam - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a cutting property when a wide sheet-like foam is split into a plurality of narrow widths, or cut into various shapes using a fusing blade, or when creating various shapes of dents on the foam surface. The present invention relates to a foam having improved workability and slippage during processing. Moreover, the foam which can be preferably used as a mold member used to form uneven patterns such as various joint patterns on the inner and outer surfaces of buildings such as murals, ceilings and floors, and road surfaces such as roads and passages It is about. Furthermore, the present invention relates to a foam having an improved blocking property of a foam which has a smooth surface and is easily blocked during storage at high temperatures.
[0002]
[Prior art]
Olefin-based resin foams have excellent cushioning properties, cushioning properties, water resistance, and chemical properties. Therefore, heat insulation materials for home appliances such as coolers, packaging cushioning materials for high-end products, packing for containers, adhesive tapes, or long It has been widely used as a heat insulating material for a lengthy roof, or a pipe heat insulating material processed into a pipe shape for temperature control. In these diverse fields, various processes are applied to produce products. As an example, when foam is used as a flexible heat-insulating hose, a wide sheet-like foam is split into many narrow pieces at once. In addition, there is a construction method in which the narrow split product is connected and continuous to be molded into a flexible heat insulating hose. When such split processing is performed, there is a problem in that the sheet-sliding property is poor and the sheet-like foam or the narrow split product is stretched or sticks to the split blade due to the tension.
[0003]
In addition, when a foam is used for heat insulation for floor heating, there is a case where a process for providing a recess for embedding a hot water flow pipe is provided in the foam, but in such a process, foaming is performed using a fusing blade. If the surface of the body is dented, there is a problem that the foam is likely to be fused to the blades by heat, and the workability tends to deteriorate.
[0004]
Furthermore, as a method of forming uneven patterns such as various joint patterns on the surfaces of buildings such as walls, ceilings and floors, road surfaces such as roads and passages, in recent years, After a mold member such as cardboard or foam is attached to a wall surface or the like, the spray material or coating material is sprayed or applied, and after the spray material or coating material is dried and solidified, the mold member is peeled off. However, there is a problem that when the spraying material or coating material is dried and solidified, it is joined to the mold member, and the mold member becomes difficult to peel off and cannot be easily removed. It was.
[0005]
[Problems to be solved by the invention]
The main object of the present invention is to provide a foam that can improve the slipperiness of such a foam and can be processed without any problems in terms of running performance during split processing, split performance, and fusing cutability.
In addition, as a mold member used to form an uneven pattern such as a joint pattern on the surface of a building such as a wall surface, a ceiling, a floor or the like, a road, a road surface such as a road, the mold member can be easily removed, Another object is to provide a foam capable of forming a concavo-convex pattern on the surface very easily and reliably.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an olefin-based resin-crosslinked foam having closed cells , wherein one or more of stearic acid, metal stearate and stearamide are 0.2 to 2.0. It consists of an olefin-based resin foam containing 1% by weight and containing 0.01 to 1.0% by weight of dimethylpolysiloxane .
Further, the present invention is an olefin resin cross-linked foam having closed cells, containing 0.2 to 2.0% by weight of magnesium stearate and 0.01 to 1.0% by weight of organopolysiloxane. % Olefin resin foam .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Details of the present invention will be described below.
As the olefin resin forming the olefin resin foam of the present invention, polyethylene resin alone, polyethylene resin obtained by copolymerizing polyethylene acetate with vinyl acetate, ethylene / ethyl acrylate, or the like, or a mixed polyethylene resin thereof, or Polypropylene resin alone, polypropylene resin obtained by copolymerizing polypropylene resin with ethylene or the like, or mixed polypropylene resin thereof is used.
[0008]
Examples of the polyethylene resin include polyethylene resins having a density of 0.900 to 0.965 g / cm ³ manufactured by a low pressure method, a medium pressure method, or a high pressure method, ethylene, butene, pentene, hexene, octene, 4-methylpentene, and the like. Examples thereof include linear polyethylene resins copolymerized with olefins, linear ultra-low density polyethylene resins, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, and the like. These polyethylene resins may be used alone or in combination of two or more.
Examples of polypropylene resins include propylene homopolymers, block copolymers obtained by copolymerizing propylene with α-olefins such as ethylene and butene, random copolymers, and random-block copolymers. These polypropylene resins may be used alone or in combination of two or more.
[0009]
As a suitable example of the olefin resin used in the present invention, a foam made of the polyethylene resin is preferable because of particularly good cold resistance.
In addition to the above resins, inorganic compounds, particularly inorganic compounds selected from Group II, Group III, and Group IV of the periodic table may be added for the purpose of heat resistance and foaming stability. Moreover, you may add the additive added to the composition for normal foams, such as a stabilizer and a coloring agent.
[0010]
The olefin-based resin foam of the present invention includes one or more of fatty acids having 8 to 22 carbon atoms, fatty acid metal salts and fatty acid amides (hereinafter collectively referred to as fatty acids) for improving slipperiness, and It is necessary to contain a predetermined amount of organopolysiloxane. Examples of the fatty acid include saturated linear fatty acids from octanoic acid (or caprylic acid) having 8 carbon atoms to behenic acid having 22 carbon atoms. Further, examples of unsaturated fatty acids include C12 Lindellic acid, C18 oleic acid, C22 whale oil, and the like. Examples of the fatty acid metal salt include aluminum salts, calcium salts, magnesium salts and zinc salts of the above fatty acids. Examples of the fatty acid amide include those having 8 carbon atoms to caprylic acid amides having 22 carbon atoms.
Among these, preferable representative examples include stearic acid having 18 carbon atoms, a metal salt thereof and an amide thereof. In particular, a metal stearate represented by magnesium stearate is preferable in that the initial decomposition of the foaming agent due to shear heat generation of the resin during extrusion hardly occurs.
[0011]
Examples of the organopolysiloxane include dimethylpolysiloxane produced by hydrolysis and polycondensation of dimethyldichlorosilane and trimethylchlorosilane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, polyoxyalkylenedimethylpolysiloxane, and the like. Examples thereof include silicone oil, modified silicone oil such as alkyl modification, amino modification, carboxyl modification, alkylaralkyl modification, and epoxy modification. Among these, dimethylpolysiloxane is particularly preferable from the viewpoint of safety and the like.
[0012]
The content of the fatty acid in the foam is 0.2 to 2.0% by weight with respect to the olefin resin foam. If the amount is less than 0.2% by weight, it is difficult to achieve the intended object of the present invention. On the other hand, if it exceeds 2.0% by weight, surging phenomenon and plate-out phenomenon are likely to occur during foam production, and it becomes difficult to obtain a uniform extruded sheet, or it is transferred to various rolls during the production process, causing stain defects, etc. It tends to occur. Moreover, when providing the adhesion layer in the foam of this invention, the case where adhesive strength with the adhesion layer cannot fully be maintained may occur. A particularly preferable range is 0.2 to 1.5% by weight.
Moreover, content in the foam of organopolysiloxane is 0.01 to 1.0 weight% with respect to the olefin resin foam. If the amount is less than 0.01% by weight, it is difficult to achieve the intended object of the present invention. On the other hand, if it exceeds 1.0% by weight, the plate-out phenomenon is likely to occur at the time of foam production, and it is easily transferred to various rolls during the production process, and stain defects are likely to occur. Particularly preferably, it is in the range of 0.05 to 0.5% by weight.
Use of such fatty acids, particularly fatty acid metal salts, and organopolysiloxane in combination is particularly preferred because the effects of the present invention are most remarkably exhibited.
[0013]
The olefin-based resin foam of the present invention is mixed with a predetermined amount of the above fatty acids and / or organopolysiloxane in addition to additives such as a foaming agent, a stabilizer, and a coloring agent, and is formed into a sheet with an extruder. After extrusion and crosslinking with an electron beam, the composition can be produced by foaming. As the foaming agent, for example, a thermally decomposable foaming agent such as azodicarbonamide can be used.
Prior to foaming or simultaneously with foaming, an olefin resin is subjected to silanol condensation using an ionizing radiation crosslinking method, a chemical crosslinking method using a peroxide such as dicumyl peroxide, or vinylmethoxysilane. Crosslinking can be carried out by means such as silane crosslinking or ultraviolet crosslinking by ultraviolet irradiation, but crosslinking by electron beam irradiation is desirable from the viewpoint of ease of process control. In the crosslinking, divinylbenzene, diallyl phthalate, hydroquinone dimethacrylate, or the like may be appropriately used as a crosslinking aid.
[0014]
The apparent density of the olefin resin foam of the present invention can be appropriately selected in the range of 0.02 to 0.35 g / cm ³ according to the purpose of use, but for the production of adhesive tapes, joint patterns and the like. When used as a mold member, a range of 0.06 to 0.35 g / cm ³ is particularly preferable in terms of strength and handling. When the apparent density is smaller than the above range, the strength of the foam becomes small, which is not preferable in terms of ease of use for the intended purpose. The density, in other words, the expansion ratio may be selected in consideration of the tensile strength and shear strength according to the intended application.
In addition, as a thickness of a foam, the thing of the range of 0.1-5 mm is used preferably, However It does not specifically limit and should just set suitably according to a use aspect.
The cell structure of the olefin resin foam of the present invention is a closed cell structure because high shear strength is obtained. In particular, when used as a mold member, it is necessary to have a closed cell structure in order to prevent penetration of the spray material or coating agent from the cross section of the foam. The foam having such a closed cell structure can be produced by the above-described method using a pyrolytic foaming agent.
[0015]
【Example】
Hereinafter, the present invention will be described in detail by way of examples.
In addition, the characteristic of an olefin resin foam is measured based on JISK6767.
[0016]
[Example 1]
80 parts by weight of low density polyethylene resin having a resin density of 0.92 g / cm ³ and 20 parts by weight of linear polyethylene resin copolymerized with butylene, 2.5 parts by weight of azodicarbonamide as a foaming agent, heat stabilizer A silicone concentrate (silicone content 50%) in which 0.2 parts by weight of Irganox 1010 was added and dimethylpolysiloxane oil (SH200 manufactured by Toray Dow Corning Silicone Co., Ltd.) was mixed in high density in low density polyethylene. A foam composition was prepared by adding 0.13 parts by weight (0.065 parts by weight as a polyorganosiloxane) and 0.25 parts by weight of magnesium stearate.
The obtained foam composition was mixed with a Henschel mixer and then extruded by a T-die method using an extruder to obtain a sheet-like product having a thickness of 1.4 mm. This sheet-like material was irradiated with an electron beam, and the resin was previously crosslinked, and then foamed in a 300 ° C. hot air foaming furnace to produce a sheet-like foam. The obtained foam was a crosslinked foam having a closed cell structure, and had a thickness of 2.0 mm and an apparent density of 0.14 g / cm ³ .
[0017]
Next, after providing an adhesive layer and release paper on one side of the foam, in order to form a joint pattern, the foam was punched into a predetermined mold to create a mold member. After that, the release paper was removed from the mold member and placed on the wall surface forming the joint pattern. However, the adhesive strength between the foam and the adhesive layer has sufficient strength, and the mold member was removed from the wall surface. There was no peeling or misalignment. Thereafter, a spray material mainly composed of an acrylic resin emulsion was sprayed. After the spray material was dried and solidified, the mold member was peeled off and removed from the wall surface. At this time, the spray material and the side surface of the mold member had sufficient peelability, and the mold member could be easily peeled off.
[0018]
[Example 2]
0.5 parts by weight of the same silicone concentrate (content 50%) as in Example 1 (0.25 parts by weight as polyorganosiloxane) per 100 parts by weight of low density polyethylene resin having a resin density of 0.93 g / cm ³ ) And magnesium stearate were added in the same manner as in Example 1 except that 1.0 part by weight of magnesium stearate was added, and then crosslinked by electron beam irradiation, and then a foam was prepared. The obtained foam had a closed cell structure and had a thickness of 2.1 mm and an apparent density of 0.15 g / cm ³ .
The peelability between the cross section of the foam and the spraying material containing an acrylic resin emulsion as a main component was examined in the same manner as in Example 1 and was satisfactory.
[0019]
[Comparative Example 1]
A sheet-like foam was produced in the same manner as in Example 1 except that the silicone concentrate and magnesium stearate were not added, and punched into a mold to prepare a mold member.
The peelability of the cross section of the obtained mold member made of the foam of Comparative Example 1 and the spraying material mainly composed of an acrylic resin emulsion was examined in the same manner as in Example 1, but the foam of the Comparative Example was made. The mold member was joined to the spraying agent and not only could be easily peeled off, but the mold member was cut when it was attempted to peel off with a strong force.
[0020]
[Example 3]
80 parts by weight of a low density polyethylene resin having a resin density of 0.92 g / cm ³ and 20 parts by weight of a linear polyethylene resin copolymerized with butylene, 11 parts by weight of azodicarbonamide as a foaming agent, and as a heat stabilizer Irganox 1010 is added to 0.4 parts by weight, 0.5 parts by weight of silicone concentrate (dimethylpolysiloxane content 50%) (0.25 parts by weight as polyorganosiloxane) and 1.1 parts by weight of magnesium stearate. The composition for foams was created by adding.
After mixing the obtained composition for foams with a Henschel mixer, it was extruded by a T-die method using an extruder to obtain a sheet-like product having a thickness of 1.3 mm. This sheet-like product was irradiated with an electron beam, and the resin was previously crosslinked, and then foamed in a 300 ° C. hot-air foaming furnace to produce a sheet-like foam having a width of 50 cm. The obtained foam was a crosslinked foam having a closed cell structure, and had a thickness of 3.0 mm and an apparent density of 0.035 g / cm ³ .
[0021]
Next, when the sheet-like foam was split into a thin tape with a width of 1 cm using a large number of metal blades at once, there was no problem with the sliding property of the sheet-like foam during processing, and continuous cutting was performed. In addition, the continuous processing of 5,000 m could be processed without any problem, and a beautiful narrow tape-like product could be obtained.
[0022]
[Comparative Example 2]
A sheet-like foam was produced in the same manner as in Example 3 except that the silicone concentrate and magnesium stearate were not added.
The sheet-like foam of Comparative Example 2 was subjected to split processing using a large number of metal blades as in the examples. When the foam was fused to the blades and continuously processed for about 1,000 m, The sharpness was bad and it became impossible to cleanly split. In addition, the state of the sheet-like foam during processing and running has a problem of slipperiness due to a large resistance with the sheet cradle.
[0023]
【The invention's effect】
The olefin resin foam of the present invention has the following effects.
(1) Even when a wide sheet-like foam is simultaneously and continuously split into a large number of narrow widths, it is excellent in continuous cutability and easily obtains a beautiful narrow width split product. be able to.
(2) Further, there is little resistance to the cradle and the guide roll, and a uniform narrow split product can be obtained without applying excessive tension.
(3) It is excellent in workability at the time of cutting into various shapes using a fusing blade or creating dents of various shapes.
(4) As a mold member used for forming uneven patterns such as various joint patterns on the surface such as a wall surface or a road surface, it can be preferably used because it can be easily separated from the spraying material.
(5) In the case of a smooth foam, especially a flexible foam containing an ethylene-vinyl acetate copolymer, etc., when stored at high temperatures or when subjected to corona discharge treatment to increase adhesion. However, the conventional foams have the drawback of being easily blocked, but such blocking properties can be greatly improved.

Claims (5)

An olefin resin cross-linked foam having closed cells,
Stearate, olefins or one of metal stearates and stearic acid amide containing 0.2-2.0 wt%, and comprising a dimethylpolysiloxane 0.01-1.0 wt% Resin foam. An olefin resin cross-linked foam having closed cells,
An olefin resin foam comprising 0.2 to 2.0% by weight of magnesium stearate and 0.01 to 1.0% by weight of organopolysiloxane. The olefin resin foam according to claim 2 , wherein the organopolysiloxane is dimethylpolysiloxane. The olefin resin foam according to any one of claims 1 to ³ , wherein the apparent density of the olefin resin foam is 0.02 to 0.35 g / cm ³ . Apparent density of the olefin resin foam is 0.06~0.35g / cm ^3, and, according to any one of claims 1 to 4 at least one side to the adhesive layer of an olefin resin foam is formed Olefin resin foam.