JP2000309063A - Sheet excellent in rear surface adhesiveness and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a sheet excellent in productivity and rear surface adhesiveness without generating material loss and refuse. SOLUTION: A sheet 1 excellent in rear surface adhesiveness is constituted by laminating a sponge layer comprising a foamable vinyl chloride resin compsn. and a finely foamed rear surface layer comprising a vinyl chloride resin compsn. in which microcapsules of which the shell walls comprise a thermoplastic synthetic resin are uniformly dispersed and the rear surface 2 of the sheet has projections formed by microcapsules expanded when the vinyl chloride resin compsn. is gelled under heating and/or recesses formed by the destruction of expanded microcapsules.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the adhesiveness of a back surface of a vinyl chloride sponge sheet having a design such as squeezing on the front surface used for stationery, binding sheets, reception sheets and the like to an adhesive.

[0002]

2. Description of the Related Art A sheet made of vinyl chloride is mainly bonded to paper, wood board, synthetic resin sheet, etc. via an acrylic adhesive or a hot-melt adhesive containing polyamide resin as a main component. Used for reception sheets, etc. However, the bonding surface (back surface) of the vinyl chloride sheet processed by the calendar method or the paste method is smooth, and sufficient strength can be obtained even if an adhesive is applied and the adherend such as paper is bonded. I can't get it. Therefore, the problem can be solved by roughening the back surface of the vinyl chloride sheet and anchoring the adhesive to the sheet.
Such methods include: There is a method in which the surface of a vinyl chloride sheet is buffed with sandpaper or the like to provide fine scratches. 2. If the vinyl chloride sheet is foamed, there is a so-called slicing method in which a thin skin on the surface of the foamed sheet is removed by a skin filter and a porous structure formed by exposed bubbles is used. 3. When processing a vinyl chloride sheet by the calendar method or the paste method, a backing material such as taffeta is laminated on the heated vinyl chloride resin surface, then cooled, and both are peeled off to back the vinyl chloride resin surface. There is a so-called peeling method for transferring unevenness of a material. However, in the case of using sandpaper, productivity is lowered due to clogging, and in addition to the problem of generation of dust, it is necessary to apply tension to the sheet when buffing. In particular, the rigidity test according to JIS L 1096 45 °
In the case of a soft sheet of 50 mm or less according to the Canterever method, the distortion due to this tension is large, and after cutting to a desired size such as stationery, binding sheets, reception sheets, etc., the dimensions change over time due to the influence of this distortion. A problem that the so-called dimensional stability is poor. In the slicing method, the skin filter can only be cut in half, and there is a problem of material loss and generation of dust. In the peeling method, there is a problem that dimensional stability is poor due to the tension at this time.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a sheet having excellent productivity without producing any material loss and dust and having excellent adhesiveness on the back surface.

[0004]

According to the present invention, there is provided a sheet having excellent backside adhesiveness, comprising a sponge or non-sponge skin layer,
A two-layer sheet having a finely foamed back layer made of a vinyl chloride resin composition in which shell walls are uniformly dispersed with microcapsules made of a thermoplastic synthetic resin, and the back surface of the sheet is heated. When the vinyl chloride resin is gelled, the microcapsules expand and protrude and / or break down after being expanded and collapse.

[0005] The sheet of the present invention having excellent adhesion on the back surface comprises a non-sponge skin layer mainly composed of a vinyl chloride resin or a urethane resin, and a sponge or non-sponge intermediate layer mainly composed of a vinyl chloride resin. And a three-layer sheet having a finely-foamed back layer made of a vinyl chloride resin composition in which shell walls are uniformly dispersed microcapsules made of a thermoplastic synthetic resin. When the vinyl chloride resin is gelled by heating, the microcapsules expand and protrude, and / or break and collapse after expansion.

Further, the method of producing a sheet having excellent adhesion on the back surface having fine irregularities by the paste method according to the present invention is characterized in that the sheet is a sheet having at least a sponge layer and a back surface layer, On the skin layer, a foamable vinyl chloride resin paste mixed with a thermal decomposition type chemical foaming agent is applied, and heated at a temperature lower than the decomposition temperature of the thermal decomposition type chemical foaming agent to form a pre-gelled unfoamed sponge layer. On the unfoamed sponge layer, an expandable vinyl chloride resin paste containing microcapsules containing volatile hydrocarbons encapsulated in a shell wall made of a thermoplastic synthetic resin is applied to form an ungelled back layer. Thereafter, the unfoamed sponge layer and the ungelled back layer are heated at a temperature higher than the shell capsule softening temperature of the microcapsules and the decomposition temperature of the thermal decomposition type chemical blowing agent. And the unfoamed sponge layer foams, and the microcapsules of the ungelled backside layer expand to form protrusions on the exposed surface of the backside layer and / or break after expansion to form depressions. It is characterized by.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is characterized by a sheet having extremely fine irregularities on the back surface obtained by a paste method using equipment such as a knife coater and a method for producing the same. FIGS. 1 and 2 are explanatory views of the structure and manufacturing process of a sheet obtained in an example of the present invention, respectively. The back layer of the sheet is formed by adding a plasticizer such as DOP to a vinyl chloride resin and kneading the paste into a paste, and microcapsules containing a volatile hydrocarbon in the paste, and, if necessary, a stabilizer, a filler, The pigment is uniformly dispersed to form an expandable vinyl chloride resin paste, and thinly coated on the pregelled skin layer or intermediate layer, and the coated sheet is heated by a heating furnace or the like to expand the expandable vinyl chloride. This gels the system resin paste and expands the microcapsules and / or destroys the thermoplastic synthetic resin constituting the shell wall of the microcapsules by the heat. That is, as shown in FIG. 1, the back surface 2 of the sheet 1 has fine protrusions and depressions due to the formation of protrusions such as hemispheres or holes due to destruction. This improves the physical adhesion of the back surface through the intermediary. still,
In order to enhance the adhesiveness of the back surface of the sheet, a filler having a coarse particle size may be used in combination as the filler, and fine irregularities may be provided on the back surface. The content of the microcapsules in the expandable vinyl chloride resin paste is 1 to 7 with respect to 100 parts by weight of the vinyl chloride resin.
Parts by weight are preferred. If it is less than this, the effect is diminished, and if it is more than this, the cost is simply increased. The coating thickness of the expandable vinyl chloride paste is preferably as thin as possible from the viewpoint of cost, but is preferably 0.08 to 0.20 mm in terms of the finished thickness in order not to generate a portion not coated.

[0008] The microcapsules used include thermosetting resins such as vinylidene chloride resin, copolymer resin of vinylidene chloride and acrylonitrile, copolymer resin of acrylonitrile and methyl acrylate, and copolymer resin of methacrylonitrile and methyl acrylate. A shell or wall made of a plastic resin containing a gas or liquid such as a volatile hydrocarbon and having a particle size of 10 to 30.
For example, Matsumoto Yushi Seiyaku Co., Ltd. sells various types of Matsumoto microspheres.

In the present invention, in order to give a sense of volume, a sponge layer is provided as a skin layer or an intermediate layer. As a material for the sponge layer, a copolymer resin of a monomer copolymerizable with vinyl chloride can be used in addition to a vinyl chloride homopolymer resin. A plasticizer such as DOP is added to the resin, and the resin is kneaded into a paste. A thermally decomposable chemical foaming agent and, if necessary, a stabilizer, a filler, and a pigment are dispersed uniformly to form a foamable vinyl chloride resin paste. The thickness at the time of application of the foamable vinyl chloride-based resin paste is appropriately selected depending on the desired expansion ratio and thickness after foaming, and for stationery such as a notebook, is 0.2 to 0.4 mm. For applications for receptions that are bonded to
1.0 mm. That is, it is usually 0.2 to 1.0 mm. Further, the expansion ratio of the sponge layer is preferably 2 to 5 times in order to improve the texture. The thermal decomposition type chemical foaming agent used at this time may be any as long as it has a decomposition temperature higher than the pregelling temperature of the vinyl chloride resin paste, and when the resin is a vinyl chloride homopolymer resin, azodicarboxylic acid There are amides (ADCA) and the like.
It is about 1 to 5 parts by weight with respect to parts by weight.

When a thin or hard sheet is produced by the present invention, a non-foamed non-sponge layer is provided in place of the sponge layer. As the material for the non-sponge layer, a copolymer resin of a monomer copolymerizable with vinyl chloride can be used in addition to a vinyl chloride homopolymer resin, and a plasticizer such as DOP is added to the resin and kneaded into a paste. Stabilizers as needed,
A filler and a pigment are uniformly dispersed to form a vinyl chloride resin paste. The preferable thickness of the vinyl chloride resin paste applied is 0.1 to 3.0 mm in terms of applications such as stationery, binding sheets and reception sheets.

The non-sponge skin layer of the present invention uses a vinyl chloride resin paste or a urethane resin. As the vinyl chloride resin paste, not only a vinyl chloride homopolymer resin but also a copolymer resin of a monomer copolymerizable with vinyl chloride can be used, and a plasticizer such as DOP is added to the resin and kneaded into a paste. In accordance with the above, a stabilizer, a filler, and a pigment are uniformly dispersed, and a skin layer is formed by a paste method. Urethane resins include, for example, polymer diols such as polyester diol, polyether diol, polyester ether diol, polyprolactone diol, and polycarbonate diol, and aromatic diisocyanate, aromatic triisocyanate, alicyclic diisocyanate, and alicyclic triisocyanate. Is a polyurethane obtained by reacting an organic isocyanate such as an aliphatic diisocyanate or an aliphatic triisocyanate with a low molecular compound having at least two active hydrogens represented by a low molecular diol or a low molecular diamine as a chain extender, It is used in the form of a solution or an emulsion, and a skin layer is formed by a wet coagulation method or a heat coagulation method. The thickness of the skin layer at the time of application is 0.1 to 0.5 mm in the case of a vinyl chloride resin paste, and 0.005 to 0.5 mm in the case of a urethane resin, depending on the strength of the skin layer. It is preferably 2 mm.

The production method according to the present invention will be described with reference to FIG. 2. The production line includes unwinding of release paper 3, a first coating machine, a first heating furnace, a second coating machine, a second heating furnace, and a third heating furnace. Coating machine, 3rd
It is arranged like a heating furnace and sheet winding. In the two-layer sheet composed of the skin layer of the sponge and the back layer of the fine foam, the foaming vinyl chloride-based resin paste containing the thermally decomposable chemical foaming agent prepared in advance on the release paper is applied by the second coater. It is applied and gelled at a gelling temperature in a second heating furnace. The gelation temperature at this time is lower than the decomposition temperature of the thermal decomposition type chemical foaming agent to form an unfoamed skin layer.

Next, the expandable vinyl chloride resin paste containing microcapsules prepared in advance is applied by a third coating machine, and the shell wall softening temperature of the microcapsules and the thermal decomposition type chemical foaming are applied in a third heating furnace. By heating at a temperature higher than the decomposition temperature of the agent, the unfoamed sponge layer is foamed, and the microcapsules are expanded to form projections on the exposed surface of the back surface layer and / or to break after expansion to cause depression. Form. At this time, by heating at a temperature higher than the softening temperature of the shell wall of the microcapsule, preferably at least 40 ° C., extremely fine irregularities can be generated on the exposed surface (the back surface of the sheet) in a short time. At this time, a thin skin layer is formed on the side of the release paper. The heating temperature is preferably set to a temperature slightly higher than the decomposition temperature of the thermal decomposition type chemical foaming agent from the viewpoint of quality and cost.

The softening temperature of, for example, a vinyl chloride homopolymer resin dispersed together with the pyrolytic chemical foaming agent forming the sponge layer is as low as 70 to 80 ° C., while the softening temperature of the microcapsule forming the back surface layer is reduced. The softening temperature of the thermoplastic resin used is designed to be as high as 130 to 200 ° C. for storage. In other words, the sponge layer is easily foamed and the back layer side is difficult to expand, and the necessary heating time is
The back layer tends to be longer. Prolonged heating,
Deterioration of vinyl chloride resin. Therefore, in order to shorten the heating time required for expansion and destruction of the back layer side containing the microcapsules, the thermoplastic resin of the shell wall of the microcapsules has a softening temperature lower than the decomposition temperature of the pyrolytic chemical foaming agent. It is more preferable to select one having a temperature lower by 30 ° C. or more. The softening temperature referred to in the present invention is based on a Vicat penetration test.

In the next step, the sheet obtained by cooling and curing the vinyl chloride resin is wound up. The release paper and the sheet may be peeled off on the production line or off-line.

In a three-layer sheet composed of a non-sponge skin layer, a sponge intermediate layer and a finely foamed back layer, a vinyl chloride resin or a urethane resin is formed on the sponge skin layer of the above-mentioned production method. A new skin layer is added. That is, in the first coater, a pre-prepared vinyl chloride resin or urethane resin is applied onto release paper and heated to form a skin layer, and the skin layer is foamed with the second coater in the second coater. The steps after the application of the vinyl resin paste are the same as the above-described manufacturing method.

[0017]

EXAMPLE A vinyl chloride resin paste for the skin layer, sponge layer and back layer having the composition shown in Table 1 was prepared in a production facility as shown in FIG. 1, and the target sheet was obtained by the paste method. At this time, the first heating furnace is kept at about 140 ° C. for about one minute,
About 140 ° C for about 1 minute in the heating furnace and about 19 ° C in the third heating furnace.
Charged at 5 ° C. for about 1.5 minutes. The comparative example differs from the example only in the composition of the back surface layer, and the skin layer and the sponge layer are the same as the example.

[Table 1] PVC: for skin layer: degree of polymerization of vinyl chloride resin 1100 For middle layer: degree of polymerization of vinyl chloride resin 800 For back layer: degree of polymerization of vinyl chloride resin 800 Plasticizer: DOP Stabilizer: for skin layer: AC-183 (Asahi Denka Co., Ltd.) For the middle layer: KF80A-8 (manufactured by Kyodo Yakuhin) For the back layer: AC-183 (manufactured by Asahi Denka) Blowing agent: For the middle layer: ADCA For the back layer: Matsumoto Microsphere F-85D Filler: Charcoal

(Evaluation) 35-45 g / m ^{2 of a} vinyl acetate emulsion-type adhesive was applied to a vinyl chloride resin sheet, dried appropriately, and then adhered to glossy paper (adherend) for 24 hours. After the pressure bonding, a peeling test was performed. Table 2
Figure 9 shows the results and dimensional stability.

[Table 2] (1) In the buffing method, the back surface of the sheet blended in the comparative example was buffed. (2) The sheet of the slicing method is obtained by dividing the sheet into two in the intermediate layer of the embodiment. (3) The peeling method is a method of applying the back surface layer of the sheet prepared in the comparative example, bonding the sheet to nylon taffeta, and then peeling the sheet. (4) The comparative example is a sheet having the composition of the comparative example. (5) Comparative Example ^{* 1} is a sheet of the composition of the comparative example, in which fine particles are mixed in the adhesive. Peeling state: ◎ indicates that the adherend has broken. △ indicates that the part is adhered but partially weak. Dimensional stability: After completion of processing steps such as buffing and slicing.
The degree of dimensional change after unwinding and press-cutting the wound material is shown. ◎ is excellent △ is usable as stationery × is not usable as stationery

[0019]

The sheet having excellent adhesiveness on the back side of the present invention is a vinyl chloride sponge sheet having a design such as a grain on the surface used for stationery, binding sheets, reception sheets and the like. Because the microcapsules mixed in the resin paste expand and / or break, the resin paste is gelled and fine irregularities are formed on the back surface, so that the adhesiveness with the adhesive is excellent, and glossy paper or wood board can be easily obtained. Adhesive processing is possible. Further, it is superior in dimensional stability and the like as compared with a post-processing buff method, a slicing method, a peeling method and the like.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a partially enlarged cross section showing an example of a sheet having excellent backside adhesiveness of the present invention.

FIG. 2 is a manufacturing process diagram of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 The sheet which is excellent in the backside adhesiveness 2 The backside of the sheet 3 Release paper

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B32B 27/30 101 B32B 27/30 101 C08K 7/22 C08K 7/22 9/10 9/10 C09J 7/02 C09J 7 / 02 Z // C08J 9/32 CEV C08J 9/32 CEV C08L 27/06 C08L 27/06 F-term (reference) 4D075 BB28Z BB30Z BB93Z CA12 DA04 DB38 DC38 EA14 EA29 EC41 4F074 AA36 AA48 AA35 BA01BAA23 BC13 CA29 CA46 CB61 CB74 CB84 CC08Z CC32Y CE02 CE16 CE25 CE49 CE56 CE86 DA02 DA19 DA20 DA24 DA45 4F100 AK01B AK15A AK15B AK15C AK51A AS00A BA02 BA03 BA07 BA15 BA43 CA01B DD07B DE04B DJ01 EDJB12J01 DJ01B DJB12J01 DJ01B DJB BD031 BD102 BG102 EA006 FA102 FD326 GF00 4J004 AC01 AC03 CA05 CA06 CB04 CC03 CC05

Claims (3)

[Claims] 1. A sponge or non-sponge skin layer, and a finely foamed back layer made of a vinyl chloride resin composition in which shell walls are uniformly dispersed with microcapsules made of a thermoplastic synthetic resin. The sheet of the layer, wherein the back surface of the sheet is characterized in that the microcapsules expand and protrude and / or break and collapse after expansion when gelling the vinyl chloride resin by heating. Sheet with excellent adhesion. 2. A non-sponge skin layer mainly composed of a vinyl chloride resin or urethane resin, a sponge or non-sponge intermediate layer mainly composed of a vinyl chloride resin, and microcapsules whose shell wall is made of a thermoplastic synthetic resin. And a finely-foamed back layer made of a vinyl chloride resin composition in which the vinyl chloride resin composition is uniformly dispersed, wherein the back surface of the sheet has microcapsules when the vinyl chloride resin is gelled by heating. A sheet having excellent back surface adhesiveness, wherein the sheet expands and protrudes and / or collapses after being expanded. 3. A method for producing a sheet having excellent adhesion on a back surface having fine irregularities by a paste method, wherein the sheet is a sheet having at least a sponge layer and a back surface layer, and a release paper or a skin layer. An expandable vinyl chloride-based resin paste mixed with a thermal decomposition type chemical foaming agent is applied thereon, and heated at a temperature lower than the decomposition temperature of the thermal decomposition type chemical foaming agent to form a pre-gelled unfoamed sponge layer, On the unfoamed sponge layer, an inflatable vinyl chloride resin paste containing microcapsules containing volatile hydrocarbons encapsulated in a shell wall made of a thermoplastic synthetic resin is applied to form an ungelled back layer, and thereafter The unfoamed sponge layer and the ungelled back layer are heated at a temperature higher than the shell wall softening temperature of the microcapsules and the decomposition temperature of the thermal decomposition type chemical foaming agent. Then, the unfoamed sponge layer is foamed, and the microcapsules of the ungelled backside layer expand to form projections on the exposed surface of the backside layer and / or break after expansion to form depressions. A method of manufacturing a sheet having excellent backside adhesion.