JP2001309830A - Desk cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desk cover which is made of a soft acrylic resin, and is resistant to ink soil of copy paper. SOLUTION: This is a desk cover which consists of a soft acrylic resin sheet containing fatty acid amide and/or metal soap in an 0.1-3.0 weight percent. And this desk cover consists of plural layers of acrylic soft resin sheet and at least a bottom layer is a soft acrylic resin sheet containing fatty acid amide and/or metal soap at 0.1-3.0 weight percent to the acrylic soft resin. And when the fatty acid amide and/or metal soap are compounded, antioxidant is also preferably to be compounded together in 0.1-2.0 weight percent to the soft acrylic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desk mat using an acrylic soft resin as a material.

[0002]

2. Description of the Related Art Desk mats are conventionally made of a resin composition in which a plasticizer, a stabilizer and the like are blended with a polyvinyl chloride resin. The mat made of polyvinyl chloride resin has excellent properties such as transparency, flexibility and good heat stability, but the plasticizer bleeds out to the mat surface during use, for example, in a desk mat, There is a disadvantage that undesired phenomena such as the printing ink of the copy paper sandwiched between the desk and the desk mat adhering to the surface of the desk mat are caused. Therefore, in recent years, desk mats made of resins other than polyvinyl chloride resins have been studied, and ethylene-based polymers such as copolymers of ethylene and alkyl (meth) acrylate, and acrylic-based soft resins have been studied. Desk mats using resin as a material have been proposed.

[0003]

The acrylic soft resin is excellent in stain resistance (stain resistance). However, it is necessary to improve the stain resistance of a desk mat using an acrylic soft resin as a material. That is, in recent years, the melting point of ink toner has been lowered with the speeding up of copiers. Therefore, when copy paper is placed between an acrylic soft resin desk mat and a desk, the printing ink on the copy paper becomes There is a problem that the lower surface (back surface) of the desk mat is stained. It is an object of the present invention to provide an acrylic soft resin desk mat that has solved this problem.

[0004]

That is, the present invention provides:
A desk mat comprising an acrylic soft resin sheet containing 0.1 to 3.0% by weight of fatty acid amide and / or metal soap. Further, in the present invention, the acrylic soft resin sheet is composed of a plurality of layers, and at least the lowermost layer thereof contains 0.1 to 3.0% by weight of fatty acid amide and / or metal soap based on the acrylic soft resin. This is a desk mat that is an acrylic soft resin sheet. When the above fatty acid amide and / or metal soap is blended, it is preferable to further blend 0.1 to 2.0% by weight of an antioxidant with respect to the acrylic soft resin.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic soft resin used in the present invention is a resin having flexibility at room temperature, such as soft polyvinyl chloride. The acrylic soft resin is preferably a polymer having a multilayer structure, that is, a polymer in which two or more acrylic polymers form a core-shell type multilayer structure. These acrylic soft resins exhibit good flexibility at room temperature, have bending durability, and are excellent in transparency and weather resistance.

An example of an acrylic soft resin is shown below. 30 to 99.9% by weight of at least one alkyl acrylate having an alkyl group having 1 to 12 carbon atoms,
0 to 70% by weight of at least one alkyl methacrylate having an alkyl group of 8 to 0 to 30% by weight of a copolymerizable unsaturated monomer, polyfunctional crosslinking monomer and / or polyfunctional graft monomer 10 to 90 parts by weight of at least one polymer layer [A] having a Tg of 30 ° C. or lower obtained by polymerizing a monomer mixture consisting of 0.1 to 10% by weight of a polymer and an alkyl having 1 to 12 carbon atoms 30 to 99% by weight of at least one alkyl acrylate having an alkyl group, 1 to 70% by weight of at least one alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms, and a copolymerizable unsaturated monomer 0 to T obtained by polymerizing a monomer mixture consisting of 30% by weight
Acrylic resin having a multilayer structure composed of a combination of 90 to 10 parts by weight of at least one polymer layer [B] having a g of −20 to 50 ° C. and an outermost layer being the polymer layer [B]. It is a soft multilayer structure resin.

Another example of an acrylic soft resin will be described. 60 to 99.5% by weight of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, 0 to 39.5% by weight of a monofunctional monomer having one copolymerizable vinyl group, and a vinyl group or vinylidene Rubber layer 30 to 8 obtained by polymerizing 0.5 to 5% by weight of a polyfunctional monomer having at least two groups
0% by weight, 40 to 100% by weight of methyl methacrylate, 0 to 60% by weight of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and a monomer having a copolymerizable vinyl group or vinylidene group And a hard resin layer obtained by polymerizing 0 to 20% by weight of a hard resin layer.

Further, another example of the acrylic soft resin will be described. (A) 80 to 98.9% by weight of methyl methacrylate, 1 to 20% by weight of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, polyfunctional grafting agent 0.0
5 to 30 parts by weight of an innermost hard polymer layer obtained by polymerizing a monomer mixture comprising 1 to 1% by weight and 0 to 0.5% by weight of a polyfunctional crosslinking agent; (B) 1 to 8 carbon atoms 70 to 99.5% by weight of an acrylic acid alkyl ester having an alkyl group of
0 to 30% by weight of methyl methacrylate, 0.5 to 5% by weight of a polyfunctional grafting agent and 0 to 5% by weight of a polyfunctional crosslinking agent
(C) methyl methacrylate 9: 20 to 45 parts by weight of a hard polymer layer as an intermediate layer obtained by polymerizing a monomer mixture comprising
An outermost hard polymer layer 50 to 7 formed by polymerizing a monomer mixture comprising 0 to 99% by weight and 10 to 1% by weight of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms.
It is an acrylic soft multilayer structure resin having 5 parts by weight and an average particle size of 0.01 to 0.3 μm.

Incidentally, the acrylic soft resin itself is supposedly excellent in stain resistance, but in recent years, the melting point of the toner tends to be lowered with the speeding up of the copying machine. When a copy paper is interposed between the desk mats, the desk mat may be stained with the print ink of the copy paper. Such stains can be prevented by blending an aliphatic amide and / or a metal soap into the acrylic soft resin. As the aliphatic amide, methylenebisstearylamide, ethylenebisstearylamide, ethylenebisoleylamide, stearylamide, oleylamide and the like are used. As the metal soap, zinc stearate, zinc oleate, lithium stearate, calcium stearate and the like are used. The compounding amount of the aliphatic amide and / or the metal soap is 0.1 to 3.0% by weight, preferably 0.5 to 2.0% by weight, based on the acrylic soft resin.

However, when an aliphatic amide and / or a metal soap is blended with an acrylic soft resin, the blended aliphatic amide and / or the metal soap are yellowed by oxidation at the time of molding, although the above advantages are obtained. The acrylic soft resin sheet may be discolored and its transparency may be reduced. In order to prevent this decrease in transparency, it is preferable to use an aliphatic amide and / or a metal soap in combination with an antioxidant. Antioxidants are classified into radical scavengers and peroxide decomposers when classified according to their functions. In the present invention, both of them are preferably used in combination.

As the above radical scavenger, pentaerythrityl-tetrakis [3- (3,5-t-butyl-4)
-Hydroxyphenyl) propionate], 2,6-di-butyl-4-methylphenol, n-octadecyl-
3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis- [methylene-3-
(3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] phenolic antioxidants such as methane and 2,2-methylenebis (4-methyl-6-t-butylphenol). Examples of the peroxide decomposer include thioether antioxidants such as dilauryl-3,3'-thiodipropionate and distearyl-3,3'-thiodipropionate, trisnonylphenylphosphite, distearyl. Examples thereof include phosphorus-based antioxidants such as pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite. The content of the antioxidant is 0.1 to 2.0% by weight, preferably 0.3 to 1.0% by weight, based on the acrylic soft resin. The acrylic soft resin may contain a plasticizer, an ultraviolet absorber, an antistatic agent, a pigment, an antiblocking agent, an antibacterial agent, a fungicide, and the like, if necessary.

The acrylic soft resin is formed into a sheet by calender molding, extrusion molding or the like. In the case of using an extruder equipped with a T-die, the sheet may be formed into a sheet having a predetermined desk mat thickness.However, in the case of using a calender, a thin sheet is formed and a plurality of sheets are laminated. It is preferable to use a sheet having a predetermined desk mat thickness. The lamination of the sheets can be performed by laminating a predetermined number of sheets and applying pressure and heat using a laminating machine. The sheet surface may be subjected to squeezing if necessary. After that, it is cut into an appropriate shape and size and processed into a desk mat shape. The thickness of the desk mat is usually 0.5 to 3 mm.

When a desk mat is manufactured by laminating a plurality of the thin sheets described above, from the viewpoint of preventing the copy paper from being stained by ink and ensuring transparency as much as possible, only the lowermost layer which is in contact with the desk during use is used. It is preferable to add an aliphatic amide and / or a metal soap (preferably in combination with an antioxidant) to the mixture. At this time, it is preferable that an aliphatic amide and / or metal soap is also blended in the uppermost layer. This is because dirt from the copy paper placed on the desk mat can be prevented.

In addition, when a thin acrylic soft resin sheet is calendered and wound into a roll, and the sheet is unwound from the roll during lamination, blocking may occur depending on the type and composition of the acrylic soft resin. Peeling of the sheets may be difficult. By blending a small amount of fatty acid amide and / or metal soap, especially fatty acid amide, the above-mentioned blocking can be eliminated without using an interleaf paper. From this viewpoint, it is preferable to mix a small amount of fatty acid amide and / or metal soap not only in the lowermost acrylic soft resin sheet in contact with the desk but also in other layers. At this time, the compounding amount of the fatty acid amide and / or the metal soap is preferably 0.05 to 0.4% by weight based on the acrylic soft resin. 0.05% by weight
Below, peeling cannot be performed easily, and when it is 0.4% by weight or more, transparency is affected. In this case, it is preferable to use an antioxidant as described above in combination. Desk mats are easily scratched for their purpose. Therefore, in the desk mat of the present invention, at least one surface thereof may be provided with a curable resin layer to prevent damage. These curable resins may be one-pack or two-pack. Ultraviolet curable resins are particularly preferably used. An ultraviolet-curable resin coating is applied to a desired surface, and then irradiated with ultraviolet light to cure the resin to form an ultraviolet-curable resin layer.

[0015]

The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1-3, Comparative Examples 1-3 Acrylic soft resin (SA-100 manufactured by Kuraray Co., Ltd.)
0-FO and GR), acrylic soft resin (W-341) manufactured by Mitsubishi Rayon Co., Ltd., metal soap (zinc stearate), fatty acid amide (methylenebisstearylamide), phenolic antioxidant (n-octadecyl) -3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate) and a phosphorus-based antioxidant (distearylpentaerythritol diphosphite) and acrylic soft resin compositions A to H shown in Table 1 Was formulated and prepared.

[0016]

[Table 1]

The acrylic soft resin composition A was extruded from a T-die by an extruder to form a 1.5 mm thick sheet (Example 1). Further, the acrylic soft resin composition F
Was extruded from a T-die using an extruder to form a sheet having a thickness of 1.5 mm (Comparative Example 1). The acrylic soft resin composition B was calendered to a thickness of 0.30 mm.
, And the acrylic soft resin composition C was calendered to form a sheet having a thickness of 0.35 mm. The acrylic soft resin compositions D, E, G, and H were each calendered to a thickness of 0. Into a .20 mm sheet.
The acrylic soft resin sheets obtained by the above-described calender molding were overlaid so as to have a layer configuration shown in Table 2, and were thermally laminated by a laminating machine (Examples 2 to 3 and Comparative Examples 2 to 3).

Next, each of the obtained acrylic soft resin sheets was cut into a desk mat shape to prepare a desk mat. For each desk mat, the presence or absence of bloom during storage at room temperature and the discoloration of each of the obtained films were examined. A copy paper was placed on the lowermost surface (back surface) of each desk mat, left at a load of 100 g / cm ² at 60 ° C. for 24 hours, and the surface of each desk mat was visually inspected for contamination.
Table 2 also shows the results. In Table 2, ○ in the column of bloom indicates no, and X indicates presence. In the item of discoloration, ◎ indicates no discoloration, ○ indicates slight discoloration, and X indicates yellowing. In the section of copy paper contamination, ○ indicates no contamination, and △ indicates slightly contaminated.

[0019]

[Table 2]

[0020]

Since the desk mat of the present invention is made of an acrylic soft resin sheet as a base material, it is soft, easy to handle, has a good feel, and has good transparency. By blending the fatty acid amide and / or the metal soap, it is possible to prevent the copy paper from being stained by the printing ink by the copying machine. When the acrylic soft resin sheet is made into a multilayer, and the layer (the lowermost layer) on the surface in contact with the desk is made of an acrylic soft resin sheet containing fatty acid amide and / or metal soap, the dirt can be removed without lowering the transparency. Can be prevented. When an antioxidant is used in combination with the fatty acid amide and / or the metal soap, it is possible to prevent a decrease in transparency due to the compounding of the fatty acid amide and / or the metal soap.

Continued on the front page (72) Inventor Tomoya Aoshima 1 Kobe, Yoshida-cho, Haibara-gun, Shizuoka Okamoto F-term in Shizuoka Plant (reference) 4F071 AA31 AA32 AA77 AC09 AC12 AE05 AE22 AF55 AH19 BC01 4J002 BG041 BN121 EG026 EG037 EG046 EJ046 EJ046 EJ067 EP016 EP026 EV067 EW067 FD077 FD206 GC00

Claims (3)

[Claims] 1. A desk mat comprising an acrylic soft resin sheet containing 0.1 to 3.0% by weight of fatty acid amide and / or metal soap. 2. An acrylic resin comprising a plurality of layers of an acrylic soft resin sheet, at least the lowermost layer of which is blended with 0.1 to 3.0% by weight of a fatty acid amide and / or a metallic soap based on the acrylic soft resin. A desk mat characterized by being a soft resin sheet. 3. A fatty acid amide and / or metal soap,
3. The composition according to claim 1, further comprising 0.1 to 2.0% by weight of an antioxidant based on the acrylic soft resin.
Desk mat described.