JPH07268292A - Heat-sensitive pressure-sensitive adhesive sheet - Google Patents

Abstract

PURPOSE:To obtain a heat-sensitive pressure-sensitive adhesive sheet which can develop a sufficient adhesive function even when the heat-sensitive pressure- sensitive adhesive layer is activated at a usual activation temperature and is excellent also in blocking resistance. CONSTITUTION:The sheet is one prepared by laying first and second heat- resistant pressure-sensitive adhesive layers each of which contains a thermoplastic resin satisfying relationship (1) and a particulate solid plasticizer satisfying relationship (2) on a support: (1) T1<=T2 (wherein T1 and T2 are the glass transition temperatures of the respective thermo-plastic resins contained in the first and second heat-sensitive pressure-sensitive material layers and (2) D1<D2 (wherein D1 and D2 are the mean particle diameters of the respective solid plasticizers contained in the first and second heat-sensitive pressure- sensitive adhesive layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive adhesive sheet which has a heat-sensitive adhesive layer which is non-adhesive at room temperature but which exhibits adhesiveness when heated and is used as a label or the like.

[0002]

2. Description of the Related Art Conventionally, labels are attached to glass bottles such as soft drinks, alcoholic beverages, and chemical bottles by applying a water-soluble adhesive such as casein or starch on the back of the label and using an automatic labeler or the like. There is a method of attaching the label, or a method of attaching a label of a general adhesive sheet having a structure in which an upper paper, an adhesive layer and a release sheet are sequentially laminated to a glass bottle using an automatic labeler or the like. However, when a water-soluble adhesive such as casein or starch is applied to the back surface of the label, the label curls and wrinkles or floats occur on the label after the label is attached to the glass bottle. In addition, the label of the adhesive sheet with a general structure is used by peeling off the release sheet at the time of use, but the peeled release sheet may be collected and reused, but in most cases it is discarded. ing. In recent years, attention has been paid to resource saving and environmental problems, and a heat-sensitive adhesive sheet that does not require a release sheet has been receiving attention.

The heat-sensitive adhesive sheet is generally known to have a structure in which a heat-sensitive adhesive layer is laminated on a base material. The heat-sensitive adhesive is composed of a thermoplastic resin, a solid plasticizer and the like, and is non-adhesive at room temperature, but is activated and develops adhesiveness when heated by a labeler or an oven provided with a heating device. Usually, the activation temperature is 50 ° C. to 150 ° C., but at these temperatures, the solid plasticizer in the heat-sensitive adhesive starts to melt and gives the thermoplastic resin adhesiveness. The melted solid plasticizer is crystallized slowly and the stickiness is maintained for a long time. Therefore, it is used by sticking it to a glass bottle or the like while having the stickiness. And even if it is continuously stuck to the glass bottle with a labeler or the like provided with a heating device, there is no problem of label failure like the method of applying a water-soluble adhesive to the back surface of the label and sticking it to the glass bottle. . Further, the heat-sensitive adhesive sheet has an advantage that it can be produced at low cost because a release sheet is not used unlike the general adhesive sheet described above.

[0004]

However, the heat-sensitive adhesive sheet has a problem that when it is stored in a place of high temperature and high humidity, the solid plasticizer in the heat-sensitive adhesive starts to melt and is blocked. The present invention provides a heat-sensitive adhesive sheet which has a sufficient adhesive function even when the heat-sensitive adhesive layer is activated at a normal activation temperature and is excellent in blocking resistance.

[0005]

The present invention provides a first heat-sensitive adhesive layer containing, on a substrate, a thermoplastic resin satisfying the following conditions and a particulate solid plasticizer in each layer. A heat-sensitive adhesive sheet comprising a second heat-sensitive adhesive layer sequentially laminated. T ₁ ≦ T ₂ (T ₁ and T ₂ are glass transition temperatures of the respective thermoplastic resins contained in the first and second heat-sensitive adhesive layers) D ₁ <D ₂ (D ₁ and D ₂ are first and Average particle diameter of each solid plasticizer contained in the second heat-sensitive adhesive layer) Further, it is preferable that D ₁ is ₂ to 4 μm and D ₂ is 6 to 10 μm. It is even better if the first heat-sensitive adhesive layer contains a tackifier.

[0006]

In the present invention, as a result of various studies, the first heat-sensitive adhesive layer having excellent adhesive function is covered with the second heat-sensitive adhesive layer having excellent blocking resistance to obtain a heat-sensitive adhesive. It has been found that the adhesive function is excellent and blocking can be prevented.

Solid plasticizers used for heat-sensitive adhesives include dihexyl phthalate (melting point 65 ° C.), dicyclohexyl phthalate (melting point 63 to 65 ° C.), dihydroabietyl phthalate (melting point 65 ° C.), isophthalic acid. Dimethyl (melting point 66-67 ° C), sucrose benzoate (melting point 98
℃), ethylene glycol dibenzoate (melting point 70 ℃),
Trimethylolethane tribenzoate (melting point 73 ° C), pentaerythritol tetrabenzoate (melting point 95 ° C), sucrose octaacetate (melting point 89 ° C), tricyclohexyl citrate (melting point 57 ° C), N-cyclohexyl-p-toluene. Examples thereof include sulfonamide (melting point 86 ° C.). Further, in the present invention, as a method for pulverizing the solid plasticizer to a desired average particle diameter, a ball mill, a sand grinder or the like can be mentioned.

The recrystallization time of the solid plasticizer once melted depends on its type. Since this time is a major factor that determines the duration of the adhesive function, when the heat-sensitive adhesive layer has two layers as in the present invention, from the viewpoint of stabilizing the duration of the adhesive function, It is preferable that the types of solid plasticizers contained in the layers are the same.

The types of thermoplastic resins as the base of the heat-sensitive adhesive include vinyl acetate-ethylene copolymer, vinyl acetate-ethylene-vinyl chloride copolymer, vinyl acetate-
Ethylene-acrylic copolymer, vinyl acetate-acrylic-
Examples thereof include styrene copolymers, vinyl acetate-acrylic copolymers, ethylene-vinyl chloride copolymers, (meth) acrylic acid ester copolymers and SBR.

It is preferable that the thermoplastic resin in the first heat-sensitive adhesive layer and the thermoplastic resin in the second heat-sensitive adhesive layer are compatible with each other. The compatibility is naturally obtained by combining the same kind, and also a combination such as a vinyl acetate-ethylene copolymer and an ethylene-vinyl chloride copolymer is obtained. The reason for this is that if these resins are compatible, the adhesive function will be stable for a long time.

The first heat-sensitive adhesive layer is provided so as to provide a sufficient adhesive force between the adherend and the substrate when used as a label or the like, and the second heat-sensitive adhesive layer. Prevents blocking of the first heat-sensitive adhesive layer and quickly transfers heat to the first heat-sensitive adhesive layer when heated and activated by a labeler or the like provided with a heating device. The activation of the heat-sensitive adhesive layer should be promoted.

Therefore, since the first heat-sensitive adhesive layer needs an adhesive function so that the label does not drop from the adherend even after being adhered to the adherend such as a glass bottle, a heating device is provided. After heat activation with a labeler, etc., the solid plasticizer in the first heat-sensitive adhesive layer should be completely melted by the heat transmitted from the second heat-sensitive adhesive layer to give tackiness to the thermoplastic resin. I have to. For that purpose, the average particle diameter of the solid plasticizer in the first heat-sensitive adhesive layer is preferably smaller than that in the second heat-sensitive adhesive layer and is 4 μm or less. More preferably, it is 2 μm to 4 μm. When the average particle size of the solid plasticizer in the first heat-sensitive adhesive layer exceeds 4 μm, the heat transferred from the second heat-sensitive adhesive layer completely removes the solid plasticizer in the first heat-sensitive adhesive layer. There is a risk that it will not melt, and if that is the case, it will not be possible to impart sufficient tackiness to the thermoplastic resin layer in the first heat-sensitive adhesive layer, and it will not be possible to develop and retain a sufficient adhesive function as a label or the like. It is impossible. Two
If it is less than μm, there is no problem in terms of performance, but in order to obtain such fine particles, it is necessary to carry out a pulverization process for a long time, which is economically meaningless.

Since the solid plasticizer of the second heat-sensitive adhesive layer has a relatively large average particle size, it has a large effect in exposing a part of the surface thereof to prevent blocking. However, if the heat-sensitive adhesive sheet is stored at a high temperature, the solid plasticizer of the second heat-sensitive adhesive layer may be exposed on the surface and may deteriorate or peel off, resulting in a long storage time. It has been found that when it extends, the adhesiveness may deteriorate during use. However, if the first heat-sensitive adhesive layer contains a sufficient solid plasticizer, it is possible to secure the adhesiveness during use after long-term storage at high temperature.

Further, the glass transition temperature of the thermoplastic resin in the first heat-sensitive adhesive layer is lower than or equal to that of the thermoplastic resin in the second heat-sensitive adhesive layer and is -35 ° C to 0 ° C. Is preferred. More preferably, it is -20 ° C to 0 ° C. When the glass transition temperature of the thermoplastic resin in the first heat-sensitive adhesive layer exceeds 0 ° C, even if the solid plasticizer in the first heat-sensitive adhesive layer is melted, the thermoplastic resin is quickly added to the thermoplastic resin. It cannot be mixed to give tackiness. Further, when the glass transition temperature is lower than -35 ° C, the adhesiveness of the first heat-sensitive adhesive layer becomes too strong, and the blocking cannot be prevented by the second heat-sensitive adhesive layer. There is a fear. A tackifier may be used to adjust the adhesive function of the first heat-sensitive adhesive layer. The types of tackifiers used in that case include rosin-based tackifiers, phenolic resin-based tackifiers, terpene resin-based tackifiers, xylene resin-based tackifiers, petroleum resin-based tackifiers, and the like. .

Since the second heat-sensitive adhesive layer must prevent blocking of the first heat-sensitive adhesive layer,
The average particle diameter of the solid plasticizer in the second heat-sensitive adhesive layer is preferably larger than that of the solid plasticizer in the second heat-sensitive adhesive layer and is preferably 6 μm or more. More preferably, it is 6 μm to 10 μm. When the average particle diameter of the solid plasticizer in the second heat-sensitive adhesive layer is less than 6 μm, it is difficult to prevent blocking because it is difficult to obtain the effect of exposing a part of the surface on the surface and preventing blocking. The second
The average particle diameter of the solid plasticizer in the heat-sensitive adhesive layer is 10μ
When it exceeds m, the solid plasticizer in the second heat-sensitive adhesive layer cannot be completely melted when it is activated at a normal activation temperature by a labeler or an oven provided with a heating device, and thus the first heat-sensitive Heat cannot be quickly transferred to the adhesive layer. The glass transition temperature of the thermoplastic resin in the second heat-sensitive adhesive layer is higher than that of the thermoplastic resin in the first heat-sensitive adhesive layer, or is about the same as that of −30 ° C. to 40 ° C. preferable. More preferably, it is 0 ° C to 30 ° C. The glass transition temperature of the thermoplastic resin in the second heat-sensitive adhesive layer is -30.
When the temperature is lower than 0 ° C, a part of the solid plasticizer is exposed on the surface, and it becomes difficult to obtain the effect of preventing blocking, which makes it difficult to prevent blocking. Further, when the glass transition temperature of the thermoplastic resin in the second heat-sensitive adhesive layer exceeds 40 ° C., the second heat-sensitive material is activated when it is activated at a normal activation temperature by a labeler or an oven provided with a heating device. Even if the solid plasticizer in the heat-sensitive adhesive layer is melted, it cannot be sufficiently mixed with the thermoplastic resin in the second heat-sensitive adhesive layer to give plasticity, and the first heat-sensitive material cannot be provided with tackiness. Heat cannot be quickly transferred to the adhesive layer.

The mixing ratio of the thermoplastic resin and the solid plasticizer in the first heat-sensitive adhesive layer is 80 to 250 solid parts by weight of solid plasticizer per 100 parts by weight of the thermoplastic resin. When the first heat-sensitive adhesive layer does not contain a solid plasticizer or contains less than 80 solid parts by weight, the thermoplastic resin and the second heat-sensitive adhesive in the first heat-sensitive adhesive layer are included. When the thermoplastic resins in the agent layer are compatible with each other, the adhesive function is slightly lowered, but in many cases it is practically no problem. However, if the solid plasticizer in the second heat-sensitive adhesive layer is deteriorated or peeled off when it is stored at a high temperature place or stored at room temperature for a long period of time, there is a problem that the adhesive function is deteriorated. . In order to prevent such a problem, it is preferable to add 80 solid parts by weight or more of the solid plasticizer to the first heat-sensitive adhesive layer. Further, if the solid plasticizer is contained in an amount of more than 250 parts by weight, there is a problem in that the time during which the heat-sensitive adhesive has tackiness becomes short.

The mixing ratio of the thermoplastic resin and the solid plasticizer in the second heat-sensitive adhesive layer is 50 to 250 solid parts by weight of the solid plasticizer per 100 parts by weight of the thermoplastic resin. If the second heat-sensitive adhesive layer does not contain a solid plasticizer or contains less than 50 solid parts by weight, the antiblocking effect cannot be obtained. Further, if the solid plasticizer is contained in an amount of more than 250 solid parts by weight, the problem that the time during which it has tackiness as a heat-sensitive adhesive becomes short, as described above, occurs.

The compounding ratio of the tackifier in the first heat-sensitive adhesive layer is 1 based on 100 parts by weight of the thermoplastic resin.
It is preferably within 50 parts by weight of solids. When the tackifier exceeds 150 solid parts by weight, there is a problem that it has tackiness as a heat-sensitive adhesive even at room temperature.

The coating amount of the first heat-sensitive adhesive layer is preferably 5 to 50 g / m ² . More preferably 10
Is about 30 g / m ² . When the coating amount of the first heat-sensitive adhesive layer is less than 5 g / m ² , there is a problem that it cannot be used as a label because a sufficient adhesive force cannot be obtained when it is attached to a glass bottle or the like as a label. If it exceeds 50 g / m ² , the adhesive function is saturated and it is not economically preferable.

The coating amount of the second heat-sensitive adhesive layer is preferably 1 to ²⁰ g / m ² . More preferably 2
It is 10 g / m ² . When the coating amount of the second heat-sensitive adhesive layer is less than 1 g / m ² , the second heat-sensitive adhesive layer is first
It is impossible to completely cover the heat-sensitive adhesive layer, and it is impossible to prevent blocking. Further, when the coating amount of the second heat-sensitive adhesive layer exceeds 20 g / m ² , when the second heat-sensitive adhesive layer is activated at a normal temperature by a labeler equipped with a heating device, an oven, etc., the first heat-sensitive adhesive layer is formed. It becomes impossible to quickly transfer heat to.

As the method for forming the first heat-sensitive adhesive layer and the second heat-sensitive adhesive layer, brush coating, spray coating, screen printing, gravure printing, offset printing,
It is formed by various coating devices such as letterpress printing, Meyer bar coater, kiss roll coater, direct roll coater, offset roll coater, gravure roll coater, reverse roll coater, rod coater, blade coater and air knife coater. Drying can be carried out by a conventional method combined with the above apparatus for coating. Also, the drying must be done below the melting point of the solid plasticizer used. This is because if the solid plasticizer is dried at a temperature higher than the melting point of the solid plasticizer, the solid plasticizer melts during the drying and the heat-sensitive adhesive layer becomes tacky. For the above reasons, it is generally preferable that the drying temperature is 50 ° C. or lower.

Examples of the material of the substrate used in the heat-sensitive adhesive sheet of the present invention include papers, films, metal foils and the like. A barrier layer may be provided on the surface to which the heat-sensitive adhesive is applied in order to reinforce the strength or prevent the heat-sensitive adhesive from penetrating into the substrate and deteriorating the adhesive function. When used as a label, printability and the like are required. In particular, when used as a label to be attached to a glass bottle containing a liquid such as soft drink, alcoholic beverage, and chemical bottle, it is preferable to use a substrate having excellent water resistance. Further, an ink or the like may be added to the heat-sensitive adhesive layer to color the heat-sensitive adhesive layer, or a heat-expandable microsphere may be contained to adjust the adhesive function.

[0023]

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.
In the examples, "parts by weight" means "parts by weight of solid" unless otherwise specified.

Example 1 (Pulverizing Method of Solid Plasticizer) The solid plasticizer was mixed with an emulsifier and pulverized with a ball mill until a solid plasticizer having each average particle diameter was obtained.

(First Method for Preparing Thermosensitive Adhesive) Vinyl acetate-ethylene copolymer having a glass transition temperature of -12 ° C. (trade name; "Sumikaflex 200", manufactured by Sumitomo Chemical Co., Ltd.), 100 parts by weight, average Dicyclohexyl phthalate (made by Osaka Organic Chemical Industry Co., Ltd.) 150 having a particle size of 3 μm
By weight and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Producing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having a diameter of 8 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of one-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer by using a reverse roll coater at 5 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet.

The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesion function test adhesion. Regarding blocking resistance, two cases were evaluated: one at 40 ° C. and 10% RH or less for 3 days and one at 40 ° C. and 90% RH for 3 days. Regarding the adhesive function, two cases were evaluated, immediately after being obtained and after being stored for a long time in a high temperature atmosphere. The specific evaluation method of the adhesive function is that the heat-sensitive adhesive sheet is heat-activated in an oven heated to 110 ° C. for 15 seconds, adhered to a glass plate within 3 minutes after heat activation, and after 2 hours, at an angle of 180 degrees. The adhesive strength was measured at a speed of 0.3 m / min, and when the adhesive strength was 300 g / 25 mm or more, it was evaluated as Δ, assuming that the adhesive function had no practical problems, and when this value was not reached, It was evaluated as x because it was inferior in adhesive function, and evaluated as ◯ when it was 800 g / 25 mm or more because it had excellent adhesive function. As a typical condition for long-term storage in a high-temperature atmosphere, the heat-sensitive adhesive sheet was stored for one month under conditions of 40 ° C. and 10% RH or less without applying a load, and then the adhesive function was similarly evaluated. . The results are shown in Table 1.

[Example 2] (First method for preparing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 part by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-71”
0 "manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by weight of water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Producing Thermosensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having a diameter of 8 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of one-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer by using a reverse roll coater at 5 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Example 3] (First method for preparing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 part by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-71”
0 "manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by weight of water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Producing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumi Elite 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having a diameter of 10 μm and water were uniformly mixed to prepare a second thermosensitive adhesive having a solid content concentration of 50%.

As a base material, a reverse roll coater was used to apply 20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive to the base paper surface of a single-sided art paper having a basis weight of 82 g / m ² , and the first heat-sensitive adhesive was dried. The agent layer was formed. Then, 15 g / m ^{2 of} the second heat-sensitive adhesive is applied onto the first heat-sensitive adhesive layer using a reverse roll coater and dried to form a second heat-sensitive adhesive layer. Got The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Example 4] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-2
100 parts by weight of vinyl acetate-ethylene-acrylic copolymer (trade name; "Sumikaflex 910" manufactured by Sumitomo Chemical Co., Ltd.) at 0 ° C, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 µm. Part, 60 parts by weight of rosin-based tackifier (trade name; "Super Ester E-710" manufactured by Arakawa Chemical Industry Co., Ltd.) and water are uniformly mixed to obtain a first heat-sensitive adhesive having a solid content concentration of 50%. Created.

(Second Method for Preparing Thermosensitive Adhesive) Vinyl acetate-ethylene copolymer having a glass transition temperature of -18 ° C. (trade name; "Sumikaflex 401" manufactured by Sumitomo Chemical Co., Ltd.) 100 parts by weight, average Dicyclohexyl phthalate (Osaka Organic Chemical Industry Co., Ltd.) with a particle size of 10 μm 20
2 parts of solid content concentration 50% by uniformly mixing 0 parts by weight and water
The heat-sensitive adhesive of was prepared.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of one-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer using a reverse roll coater at 10 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Example 5] (First method for preparing heat-sensitive adhesive) Glass transition temperature-2
100 parts by weight of vinyl acetate-ethylene-acrylic copolymer (trade name; "Sumikaflex 910" manufactured by Sumitomo Chemical Co., Ltd.) at 0 ° C, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 µm. Part, 60 parts by weight of rosin-based tackifier (trade name; "Super Ester E-710" manufactured by Arakawa Chemical Industry Co., Ltd.) and water are uniformly mixed to obtain a first heat-sensitive adhesive having a solid content concentration of 50%. Created.

(Second method for producing heat-sensitive adhesive) 100 parts by weight of vinyl acetate-ethylene-vinyl chloride copolymer (trade name; "Sumikaflex 850" manufactured by Sumitomo Chemical Co., Ltd.) having a glass transition temperature of 30.degree. , 200 parts by weight of dicyclohexyl phthalate having an average particle diameter of 6 μm (manufactured by Osaka Organic Chemical Industry Co., Ltd.) and water are uniformly mixed to obtain a solid content concentration of 50.
% Secondary heat sensitive adhesive was made.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied onto the first heat-sensitive adhesive layer using a reverse roll coater at 3 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Example 6] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-3
Vinyl acetate-ethylene copolymer (trade name; "Sumikaflex 473" manufactured by Sumitomo Chemical Co., Ltd.) at 100C
Parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 μm, and 60 parts by weight of rosin-based tackifier (trade name; “Super Ester E-710” manufactured by Arakawa Chemical Industry Co., Ltd.) Water was mixed uniformly to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Thermosensitive Adhesive) 100 parts by weight of vinyl acetate-ethylene copolymer having a glass transition temperature of -3 ° C (trade name; "Sumikaflex 473" manufactured by Sumitomo Chemical Co., Ltd.), average Dicyclohexyl phthalate having a particle diameter of 10 μm (manufactured by Osaka Organic Chemical Industry Co., Ltd.) 200
By mixing the parts by weight and water uniformly, a second heat-sensitive adhesive having a solid content concentration of 50% was prepared.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer using a reverse roll coater at 7 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Comparative Example 1] (First method for preparing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 part by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-71”
0 "manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by weight of water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%. (Second Method for Preparing Thermosensitive Adhesive) Glass Transition Temperature 20
100 parts by weight of ethylene-vinyl chloride copolymer (trade name; "Sumierito 1210" manufactured by Sumitomo Chemical Co., Ltd.) at 200C, and 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) having an average particle diameter of 2 µm. Water was uniformly mixed to prepare a second heat-sensitive adhesive having a solid content of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of one-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, 2 g / m ^{2 of} the above-mentioned second heat-sensitive adhesive was applied onto the first heat-sensitive adhesive layer using a reverse roll coater and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Comparative Example 2] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-710”)
60 parts by weight of water (manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Producing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryte 1210” manufactured by Sumitomo Chemical Co., Ltd.), average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a diameter of 15 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer using a reverse roll coater at 10 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3] (Method for preparing first heat-sensitive adhesive) Glass transition temperature 20
100 parts by weight of ethylene-vinyl chloride copolymer (trade name; "Sumieryt 1210" manufactured by Sumitomo Chemical Co., Ltd.) at 150C, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 µm, rosin 60 parts by weight of a system tackifier (trade name; "Super Ester E-710" manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Thermosensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a diameter of 10 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, 25 g / m ^{2 of} the second heat-sensitive adhesive is applied onto the first heat-sensitive adhesive layer using a reverse roll coater and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-4
Ethylene-special ester copolymer at 0 ° C (trade name; "Sumikaflex 920" manufactured by Sumitomo Chemical Co., Ltd.) 1
00 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-71”
0 "manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by weight of water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Producing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumi Elite 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a diameter of 7 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper surface of one-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer using a reverse roll coater at 10 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 5] (First method for producing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 3 μm, rosin-based tackifier (trade name; “Super Ester E-710”)
60 parts by weight of water (manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Thermosensitive Adhesive) Ethylene-special ester copolymer having a glass transition temperature of -40 ° C. (trade name; "Sumikaflex 920" manufactured by Sumitomo Chemical Co., Ltd.) 100 parts by weight, average Dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a particle diameter of 10 μm 20
2 parts of solid content concentration 50% by uniformly mixing 0 parts by weight and water
The heat-sensitive adhesive of was prepared. 82 g / m2 as a base material
The original paper of ² single-sided art paper, the first heat-sensitive adhesive 20 g / m ² applied using a reverse roll coater,
It dried and formed the 1st thermosensitive adhesive layer. Then, on the first heat-sensitive adhesive layer, 5 g / m ^{2 of} the above-mentioned second heat-sensitive adhesive was applied using a reverse roll coater and dried to obtain the second heat-sensitive adhesive.
The heat-sensitive adhesive layer was formed to obtain a heat-sensitive adhesive sheet.
The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 6] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 μm, rosin-based tackifier (trade name; “Super Ester E-710”)
60 parts by weight of water (manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Thermosensitive Adhesive) Acrylic copolymer having glass transition temperature of 45 ° C. (trade name: “ES-
20 "Chuo Rika Kogyo Co., Ltd.) 100 parts by weight, 200 parts by weight of dicyclohexyl phthalate (Osaka Organic Industry Co., Ltd.) having an average particle diameter of 8 μm and water are uniformly mixed to obtain a second heat-sensitive material having a solid content concentration of 50% A pressure sensitive adhesive was prepared.

A first roll of the first heat-sensitive adhesive was coated with 20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive using a reverse roll coater on the base paper surface of a single-sided art paper having a basis weight of 82 g / m ² as a base material. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer by using a reverse roll coater at 5 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Comparative Example 7] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle size of 8 μm, rosin-based tackifier (trade name; “Super Ester E-710”)
60 parts by weight of water (manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Thermosensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a diameter of 10 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

As a base material, the first heat-sensitive adhesive agent was applied at 20 g / m ² on a base paper surface of a single-sided art paper having a basis weight of 82 g / m ² using a reverse roll coater and dried to obtain the first heat-sensitive adhesive agent. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer using a reverse roll coater at 10 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 8] (Method for preparing first heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 part by weight, 80 parts by weight of a rosin-based tackifier (trade name; "Super Ester E-710" manufactured by Arakawa Chemical Industry Co., Ltd.) and water are uniformly mixed to form a first heat-sensitive adhesive having a solid content of 50%. The agent was created.

(Second Method for Producing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210”, manufactured by Sumitomo Chemical Co., Ltd.), average particle 200 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having a diameter of 8 μm and water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, the second heat-sensitive adhesive is applied on the first heat-sensitive adhesive layer by using a reverse roll coater at 5 g / m ² and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[Comparative Example 9] (First method for preparing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C. (trade name; “Sumikaflex 200”, manufactured by Sumitomo Chemical Co., Ltd.) 100
Parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 μm, and 60 parts by weight of rosin-based tackifier (trade name; “Super Ester E-710” manufactured by Arakawa Chemical Industry Co., Ltd.) Water was mixed uniformly to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Heat-Sensitive Adhesive) Ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumilite 1210” manufactured by Sumitomo Chemical Co., Ltd.) and water are uniformly mixed. Then, a second heat-sensitive adhesive having a solid content concentration of 50% was prepared. The original paper of one-sided art paper basis weight 82 g / m ² as a base material, the first heat-sensitive adhesive 20 g / m ² applied using a reverse roll coater, and dried to first heat-sensitive adhesive layer Formed. Then, 2 g / m ^{2 of} the above-mentioned second heat-sensitive adhesive was applied onto the first heat-sensitive adhesive layer using a reverse roll coater and dried to form a second heat-sensitive adhesive layer. Got the sheet. The resulting heat-sensitive adhesive sheet was evaluated for blocking resistance and adhesive function in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 10] (First method for preparing heat-sensitive adhesive) Glass transition temperature-1
Vinyl acetate-ethylene copolymer at 2 ° C (trade name; "Sumikaflex 200" manufactured by Sumitomo Chemical Co., Ltd.) 10
0 parts by weight, 150 parts by weight of dicyclohexyl phthalate (manufactured by Osaka Organic Industry Co., Ltd.) having an average particle diameter of 2 μm, rosin-based tackifier (trade name; “Super Ester E-710”)
60 parts by weight of water (manufactured by Arakawa Chemical Industry Co., Ltd.) and water were uniformly mixed to prepare a first heat-sensitive adhesive having a solid content concentration of 50%.

(Second Method for Preparing Heat-Sensitive Adhesive) 100 parts by weight of ethylene-vinyl chloride copolymer having a glass transition temperature of 20 ° C. (trade name; “Sumieryt 1210” manufactured by Sumitomo Chemical Co., Ltd.) and average particles 200 parts by weight of dicyclohexyl phthalate having a diameter of 8 μm (manufactured by Osaka Organic Industry Co., Ltd.),
Rosin tackifier (trade name; "Super Ester E-
710 "manufactured by Arakawa Chemical Industry Co., Ltd.) and 60 parts by weight of water were uniformly mixed to prepare a second heat-sensitive adhesive having a solid content concentration of 50%.

20 g / m ^{2 of} the above-mentioned first heat-sensitive adhesive was applied to the base paper surface of a single-sided art paper having a basis weight of 82 g / m ² as a base material using a reverse roll coater and dried to obtain the first heat-sensitive adhesive. The agent layer was formed. Then, 2 g / m ^{2 of} the above-mentioned second heat-sensitive adhesive was applied onto the first heat-sensitive adhesive layer using a reverse roll coater and dried to form a second heat-sensitive adhesive layer. Got the sheet. The heat-sensitive adhesive sheet thus obtained was tested for blocking resistance in the same manner as in Example 1.
The adhesive function was evaluated. The results are shown in Table 1.

[0071]

[Table 1]

[0072]

EFFECT OF THE INVENTION The thermosensitive adhesive layer has a sufficient adhesive function even when activated at a normal activation temperature, has excellent blocking resistance, and does not deteriorate in adhesive function even when stored at high temperature. It is an adhesive sheet.

Claims (3)

[Claims] 1. A first layer comprising, on a base material, a thermoplastic resin satisfying the following conditions and a particulate solid plasticizer in respective layers.
2. A heat-sensitive adhesive sheet comprising the heat-sensitive adhesive layer and the second heat-sensitive adhesive layer sequentially laminated. T ₁ ≦ T ₂ (T ₁ and T ₂ are glass transition temperatures of the respective thermoplastic resins contained in the first and second heat-sensitive adhesive layers) D ₁ <D ₂ (D ₁ and D ₂ are first and Average particle size of each solid plasticizer contained in the second heat-sensitive adhesive layer) 2. The D ₁ is ₂ to 4 μm and the D ₂ is 6 to 10 μm.
The heat-sensitive adhesive sheet according to claim 1, which is m. 3. The heat-sensitive adhesive sheet according to claim 1, wherein the first heat-sensitive adhesive layer contains a tackifier.