JP4225922B2 - Polyolefin resin foam sheet - Google Patents

Description

  The present invention relates to a foamed sheet made of an olefinic resin used for stationery, various cases, packaging, furniture, and the like, and more particularly to a flexible olefinic resin foamed sheet.

  Conventionally, foam sheets and laminates made of various synthetic resins have been used for stationery, various cases, packaging, furniture, and the like. Conventionally, foam sheets and laminates made of polyvinyl chloride resin or polyurethane resin have been mainly used. These sheets are used as artificial leather by providing a three-dimensional design with a concavo-convex pattern on the surface or a printed pattern or the like on the surface.

  However, when a polyvinyl chloride resin is used, there are problems that the contained plasticizer begins to stain and yellows or becomes sticky, and that there are problems of poor cold resistance and oil resistance. In addition, since a large amount of plasticizer is used, there is a problem that the surface of the sheet is easily soiled and is difficult to remove.

  In addition, when polyurethane resin is used, there is no problem of bleeding out of the plasticizer. However, if it is used for a long time or under conditions of high temperature and humidity, the hydrolysis reaction proceeds and it tends to become brittle. There was a problem with durability.

  Then, the use application of such a foam sheet and a laminated body spreads further, and what has the physical property and characteristic which were not in the past is needed.

  Thus, foam sheets and laminates made of olefin resins have been attracting attention. As the olefin resin to be used, polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer and the like are used.

Japanese Patent Laid-Open No. 09-165462

  However, the foam sheet and laminate made of the olefin resin as described above are hard to feel in the touch feeling and the like, and compared with those using conventional polyvinyl chloride resin or polyurethane resin. Thus, the texture is inferior and the usage is limited.

  In addition, since the foam sheet is hard, when the surface is processed into a concavo-convex pattern or the like, the concavo-convex pattern is difficult to enter, the processing time is long, and the workability is poor. It was inferior to the case where resin was used.

  The present invention was made to solve the above problems, and in a polyolefin resin foam sheet using a polyolefin resin, it is equivalent to using a conventional polyvinyl chloride resin or polyurethane resin in the texture, etc. It is an object of the present invention to provide a foam sheet having little change with time and excellent in light resistance and durability.

The polyolefin resin foam sheet of the present invention made to solve the above problems is a JIS A hardness meter with respect to 100 parts by weight of a polyolefin resin containing at least one of the following (1) to (3). A polyolefin resin in which a base resin to which 50 to 300 parts by weight of polyolefin rubber of 60 or less is added is used to prepare a foamable sheet and the resulting foamable sheet is heated to increase the expansion ratio to 3 to 15 times. It is characterized in that at least one of a base fabric layer and a skin layer is laminated on a resin foam sheet. As the time of lamination, even after forming a foam sheet, it may be bonded in the state of a foam sheet before foaming and then foamed.
(1) an ethylene-vinyl acetate copolymer resin having a vinyl acetate component of 15 to 30% by weight,
(2) an ethylene- (meth) acrylic acid ester copolymer resin in which the (meth) acrylic acid ester component is 15 to 30% by weight,
(3) An ethylene-high alpha olefin copolymer resin in which the high alpha olefin component having 6 or more carbon atoms is 15 to 30% by weight.

  The polyolefin resin of the present invention is preferably a copolymer resin because of its good flexibility and foamability, and more preferably an ethylene-vinyl acetate copolymer resin, an ethylene- (meth) acrylate ester copolymer. It is desirable to use at least one of a coalesced resin and an ethylene-high alpha olefin copolymer resin.

  As the ethylene-vinyl acetate copolymer resin, a vinyl acetate component having a content of 5 to 30% by weight, particularly 15 to 30% by weight considering the foamability and texture (softness) of the obtained foam sheet is preferable. It is. If it exceeds 30% by weight, the heat deformability tends to increase, and the cost is not preferable.

  Of course, this ethylene-vinyl acetate copolymer resin may be a mixture of resins having different vinyl acetate contents. Moreover, as long as the characteristics of the obtained foam sheet are not impaired, the monomer component other than ethylene and vinyl acetate may be copolymerized.

  Examples of the ethylene- (meth) acrylate copolymer resin include an ethylene-methyl methacrylate copolymer resin, an ethylene-methyl acrylate copolymer resin, and an ethylene-ethyl acrylate copolymer resin. Preferably, the (meth) acrylic acid ester component is 5 to 30% by weight, particularly 15 to 30% by weight considering the foamability and texture (softness) of the resulting foam sheet. is there. If it exceeds 30% by weight, the heat deformability tends to increase, and the cost is not preferable.

  Of course, this ethylene- (meth) acrylic acid ester copolymer resin may be a mixture of different types of (meth) acrylic acid esters copolymerized with ethylene and their contents.

  Moreover, if it is a range which does not impair the characteristic of the foam sheet obtained, monomer components other than ethylene and (meth) acrylic acid ester may be copolymerized.

  Examples of the ethylene-high alpha olefin copolymer resin include an ethylene-hexene copolymer resin, an ethylene-octene copolymer resin, and the like. In consideration of the foamability and texture (softness) of the obtained foam sheet, those of 15 to 30% by weight are preferred. If it exceeds 30% by weight, the heat deformability tends to increase, and the cost is not preferable.

  Of course, this ethylene-high alpha olefin copolymer resin may be a mixture of different types of high alpha olefin resins copolymerized with ethylene, different contents, etc., and having less than 6 carbon atoms. Even if a thing is contained, what is 6 or more should just be 5 to 30 weight%.

  Moreover, as long as the characteristics of the obtained foam sheet are not impaired, the monomer components other than ethylene and the high alpha olefin resin may be copolymerized.

  One or more polyolefin-based resins selected from ethylene-vinyl acetate copolymer resin, ethylene- (meth) acrylic ester copolymer resin, and ethylene-high alpha olefin copolymer resin forming the foam sheet are JIS A An olefin rubber having a hardness of 60 or less is added as measured with a hardness meter. If the hardness exceeds 60, it is difficult to obtain a soft foam sheet having a good texture. As the olefin rubber, ethylene-propylene rubber, ethylene-butene rubber, propylene-ethylene rubber, propylene-butene rubber and the like can be used. As addition amount, 50-300 weight part is preferable with respect to 100 weight part of polyolefin-type copolymer resin. If the addition amount is less than 50 parts by weight, it becomes difficult to obtain a soft foam sheet having a good texture, and if it exceeds 300 parts by weight, it is not preferable in terms of workability and quality characteristics.

  A foaming agent is added to foam a base resin obtained by adding a polyolefin rubber to a polyolefin resin. As a blowing agent used, a kind selected from thermal decomposition type chemical blowing agents such as azodicarboxamide, oxybisbenzenesulfonyl hydrazide, benzenesulfonyl hydrazide, P-toluenesulfonyl hydrazide, diazoaminobenzene, azobisisobutyronitrile, etc. Alternatively, two or more kinds can be used in combination.

The addition amount of said foaming agent is suitably selected according to the expansion ratio of the desired foam sheet. For example, when the expansion ratio is about 3 to 15 times, it is about 2 to 20 parts by weight per 100 parts by weight of the base resin.
If necessary, various additives such as an antistatic agent, an antioxidant, a light stabilizer such as a hindered amine compound, a lubricant, an ultraviolet absorber, an inorganic filler, and a colorant such as a pigment may be added.

  What is necessary is just to mix | blend polyolefin resin, polyolefin rubber, a foaming agent, and a desired additive, and to knead | mix by each known means. Examples thereof include a method using a pressure kneader, a roll, a Banbury mixer, a static mixer, a screw type extruder, and the like. Depending on the case, what dry-blended each component beforehand may be kneaded.

  After kneading, a foamable sheet having a desired thickness is obtained by a calendar roll, a knife coating method or the like. For example, the temperature of the calendar roll at this time is preferably 100 to 150 ° C. at which the foaming agent does not foam.

  The obtained foamable sheet is heated to obtain the polyolefin resin foam sheet of the present invention. The heating temperature needs to be equal to or higher than the thermal decomposition temperature of the foaming agent, and is usually about 160 to 220 ° C.

  Further, if desired, one or both of a skin layer and a base fabric layer may be laminated and bonded to each surface of the foamable sheet to form a two-layer or three-layer structure, and then heated to foam. To obtain the laminated polyolefin resin foam sheet of the present invention. By providing the skin layer and the base fabric layer, it is possible to improve the physical properties and the like of the foam sheet of the present invention, and the use that can be used can be expanded.

  As the skin layer, a non-foamed synthetic resin layer is usually used. The laminated polyolefin resin foam sheet of the present invention is preferably an olefin resin skin layer, and may be the same resin composition as that of the foamable sheet except for the foaming agent. If it is the same olefin resin as a foam sheet | seat, it is preferable in terms of physical properties, such as durability, and can also be easily performed in a disposal process.

  The production of the skin layer may be carried out by a normal synthetic resin sheet production method as in the case of the foamable sheet.

  As the base fabric layer, various fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics used for ordinary synthetic resin leather and synthetic leather can be used. For example, woven fabrics such as cotton, rayon, polyester, and polyamide. And various non-woven fabrics such as synthetic resin fibers such as knitted fabric, polyethylene, polypropylene, and polyester.

  The method for bonding the foam sheet to the skin layer and the base fabric layer can be applied to any method as long as it is a commonly practiced method, and is appropriately selected in consideration of the characteristics of the foam sheet, the skin layer and the base fabric layer. Is done. For example, when the foam sheet and the skin layer are bonded together, they can be bonded through a heating roll or the like in a laminated state. In addition, if necessary, an adhesive layer or a primer layer may be provided between the two layers to bond together to improve the adhesion between the layers. For example, ethylene-vinyl ester copolymer resin system, vinyl acetate A hot melt type such as a resin type or a urethane resin type or a reaction type can be used.

  In addition, as the time of pasting, even after the foamable sheet is heated and foamed to obtain the foamed sheet of the present invention, the foamed sheet before foaming may be pasted together and then foamed. When using a non-heat-resistant material for the skin layer or the base fabric layer, it is preferable that the layers are bonded after foaming because the possibility of damaging the properties of the skin layer or the base fabric layer is reduced.

  Furthermore, after providing a foamable sheet layer directly on the skin layer or the base fabric layer by a knife coating method or the like, a skin layer or a base fabric layer is bonded to the surface of the foamable sheet layer as necessary to form a three-layer structure. Alternatively, foaming may be performed thereafter. Of course, it is good also as a three-layer structure after foaming.

As detailed above, the polyolefin resin foam sheet of the present invention, the polyolefin resin foam sheet having a skin layer or a base fabric layer, and the polyolefin resin foam sheet having a skin layer and a base fabric layer are conventional olefins. Compared with the resin-based foam sheet, the texture is excellent. In addition, compared with polyvinyl chloride or polyurethane foam sheet, it has the same performance in terms of texture, and is excellent in other durability.

  The present invention will be described below based on specific examples, but the present invention is not limited to the following examples.

  The foamable sheet composition having the composition shown in Table 1 was kneaded with a Banbury mixer.

* Ultrasen 634 (manufactured by Tosoh Corporation): ethylene-vinyl acetate copolymer resin * Acrylift WH-202 (manufactured by Sumitomo Chemical Co., Ltd.): ethylene-methyl methacrylate copolymer resin -Octene copolymer resin * Tuffmer (Mitsui Chemicals): Three types of olefin-based rubbers with JIS A hardness of 41, 55, and 65 are used. Thus, the foam sheets of the present invention were prepared, and the respective foam sheets 1 to 10 were evaluated.
(Manufacturing method 1)
Each formulation in Table 1 was mixed by a Banbury mixer, and a foamable sheet having a thickness of 0.5 mm and a width of 820 mm was prepared using a 120 ° C. calender roll, and this sheet was heated in an oven heated to 190 ° C. Passing for 2 minutes, a foam sheet having a thickness of 1.5 mm was obtained.

The foam sheet 10 was not improved in the texture due to the amount of olefin rubber added.
(Manufacturing method 2)
The blends 11 to 13 shown in Table 3 below were mixed by a Banbury mixer, a sheet of 0.2 mm thickness x 820 mm width was prepared using a calender roll at 120 ° C., and foaming of the blend 1 prepared in the production method 1 was made. After heat laminating to the adhesive sheet, each sheet was passed in an oven heated to 190 ° C. for 2 minutes to obtain a foam sheet having a skin layer having a thickness of 1.7 mm. The foam sheet having each skin layer had a good texture.

(Manufacturing method 3)
Formulation 1 was made in the same manner as in Production Method 1, a foamable sheet having a thickness of 0.3 mm × width of 820 mm was prepared, and a knitted fabric having a width of 910 mm was bonded thereto, and then Compound 11 was made in the same manner as in Production Method 2. Then, a sheet having a thickness of 0.1 mm and a width of 820 mm is prepared, and this sheet is calendar-topped on the side of the foam sheet that is not bonded to the melias cloth to form a foam sheet having a skin layer and a base fabric layer. The sheet was passed in an oven heated to 190 ° C. for 2 minutes to obtain a foamed leather having a thickness of 1.2 mm having a skin layer and a base fabric layer.

  This foamed leather was superior in texture compared to conventional olefin-based leather.

Claims (1)

A base resin in which 50 to 300 parts by weight of a polyolefin rubber of 60 or less is added with a JIS A hardness meter to 100 parts by weight of a polyolefin resin containing at least one of the following (1) to (3) : Then, a foamable sheet is prepared, and the resulting foamable sheet is heated to laminate at least one of a base fabric layer and a skin layer on a polyolefin resin foam sheet having a foaming ratio of 3 to 15 times. A polyolefin resin foam sheet characterized by having been made.
(1) an ethylene-vinyl acetate copolymer resin having a vinyl acetate component of 15 to 30% by weight,
(2) an ethylene- (meth) acrylic acid ester copolymer resin in which the (meth) acrylic acid ester component is 15 to 30% by weight,
(3) An ethylene-high alpha olefin copolymer resin in which the high alpha olefin component having 6 or more carbon atoms is 15 to 30% by weight.