JP2011079280A - Foaming resin composite structure and packaging material using it as cushioning material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a foaming resin composite structure with excellent impact resistance. <P>SOLUTION: The working environmental temperature of a cushioning material 50 is 0-60°C, the resin film 53 thereof has tensile strength of 0.6-37 MPa, and has a tensile breakage elongation of 8-2,000% when the film thickness is 500 μm. Therefore, even when a load F1 is applied to a surface 51a of the cushioning material 50 and a base material 51 is rapidly deformed as shown in Fig.2(a), a resin film 53 is deformed following the base material 51 and hardly causes breakage, so that the base material is hardly broken as shown in Fig.2(b). As shown in Fig.2(c), even if a load F2 larger than the load F1 is applied and the base material 51 is broken, the resin film 53 is hardly broken, so that the impact by the load F2 can be absorbed by the resin film 53, thereby further increasing impact resistance of the cushion material 50 than before. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a foamed resin composite structure in which a resin film is formed on a predetermined surface of a base material made of foamed resin and can improve impact resistance, and a packaging material using the same as a cushioning material.

  Foamed resin molded products typified by styrene are excellent in light weight, heat insulating properties, buffer properties, flexibility, and the like, and are therefore used in buffer materials, heat insulating materials, various containers, and the like. However, when the foaming ratio is increased in order to give priority to lightness, there are disadvantages such as the surface of the molded product is brittle and the mechanical strength is low. Therefore, conventionally, as a foamed resin composite structure that can compensate for such drawbacks, a foamed resin base material in which a film made of an epoxy resin, an unsaturated polyester resin, or a urethane resin is formed (Patent Documents 1 to 4). In addition, a material obtained by applying and curing a specific paint (Patent Document 5) is known.

JP 58-63440 A JP-A-8-276934 JP-A-10-120808 JP 2006-198933 A JP 2002-20531 A

FIG. 30 is an explanatory diagram when a load is applied to the conventional foamed resin composite structure described above, (a) is a longitudinal sectional view of the foamed resin composite structure, and (b) is an application direction of the load. Explanatory drawing of (c) is a longitudinal cross-sectional view of the destroyed foamed resin composite structure. As shown in FIG. 30A, a conventional foamed resin composite structure 80 is formed by forming a resin film 82 on the surface of a foamed resin molded body 81.
However, as shown in FIG. 30 (b), when the conventional foamed resin composite structure 80 is rapidly deformed by applying a load F1 to the surface, the resin film 82 cannot be deformed following the deformation, As shown in FIG. 30 (c), it may be destroyed.
That is, there is a problem that the conventional foamed resin composite structure is inferior in impact resistance.

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to realize a foamed resin composite structure excellent in impact resistance.

  In order to achieve the above object, the first feature of the present invention is that the tensile strength is 0.6 to 37 MPa at a use environment temperature of 0 to 60 ° C., and the tensile fracture elongation is 8 when the film thickness is 500 μm. ~ 2000% of the resin film (indicated by reference numeral 53 in FIG. 1) is formed on the surface (51b) opposite to the surface (51a) on which at least the load (F1) is applied in the base material (51) made of foamed resin. The foamed resin composite structure (50) is formed.

  The second feature of the present invention is that, in the first feature described above, the resin film (53) is also formed on the surface (51a) on which the load (F1) is applied.

  According to a third feature of the present invention, in the first or second feature described above, the resin film (53) is at least one of acrylic, synthetic rubber, vinyl acetate, ethylene, epoxy, and urethane. That is, it is formed by applying a coating material containing at least a solvent-type or dispersion-type resin consisting of two to the base material (51).

  According to a fourth feature of the present invention, in the first or second feature described above, the resin film (53) includes at least a solventless resin composed of at least one of acrylic, epoxy, and urethane. The coating material is formed by coating the base material (51).

  According to a fifth feature of the present invention, in the third or fourth feature described above, the resin is an acrylic emulsion.

  A sixth feature of the present invention is that, in the fifth feature described above, the resin is a room temperature crosslinking acrylic emulsion.

  A seventh feature of the present invention is that in any one of the third to sixth features described above, the coating material is formed by mixing at least a plurality of types of resins.

  An eighth feature of the present invention resides in that, in any one of the first to seventh features described above, the glass transition temperature of the resin film is −30 to 38 ° C.

  A ninth feature of the present invention is that, in the eighth feature described above, the glass transition temperature of the resin film (53) is -30 to 25 ° C, and the use environment temperature is a normal temperature of 5 to 35 ° C. is there.

  A tenth feature of the present invention is that, in the ninth feature described above, the glass transition temperature is -17 to 20 ° C.

  According to an eleventh feature of the present invention, in any one of the eighth to tenth features described above, the coating material contains an additive in a resin having a glass transition temperature outside the range of the glass transition temperature. It is to be a thing.

  A twelfth feature of the present invention is that in any one of the third to eleventh features described above, the coating material contains a filler in a resin.

  A thirteenth feature of the present invention is that in any one of the third to twelfth features described above, the coating material contains a drug.

  A fourteenth feature of the present invention is that, in any one of the third to thirteenth features described above, the coating material contains a conductive material.

  A fifteenth feature of the present invention is that in any one of the third to fourteenth features described above, the coating material contains a magnetic material.

  A sixteenth feature of the present invention is that, in any one of the first to fifteenth features described above, the thickness of the resin film (53) is at least 50 μm or more.

  According to a seventeenth feature of the present invention, in any one of the first to sixteenth features described above, the resin film (53) is in close contact with the base material (51), and from an end portion. It is to be able to be peeled off.

  According to an eighteenth feature of the present invention, in any one of the first to seventeenth features described above, a load is applied to the surface (51a) on which the load (F1) is applied, and the base material (51) is destroyed. In this case, the resin film (53) is configured not to crack.

  According to a nineteenth feature of the present invention, in any one of the first to eighteenth features described above, the surface of the resin film (53) formed on the base material (51) has adhesiveness. is there.

  A twentieth feature of the present invention is a packaging material (60) in which the foamed resin composite structure (50) described in the nineteenth feature is disposed as a cushioning material, and is formed on the base material (51). Further, the surface of the resin film (53) is adhered to a portion of the inner surface of the packing material main body where the load to be packed is applied, thereby forming a packing material in which the foamed resin composite structure is arranged.

  Note that the base material described in the first to nineteenth features described above is obtained by filling a mold with foamed resin raw materials such as foam beads or foamed particles previously foamed at a predetermined foaming ratio. This is a foamed resin molded body as it is shaped by molding by heating and foaming, or a foamed resin molded body prepared by fusing the foamed resin molded body with heated nichrome wire or the like.

In addition, the above-mentioned foamed resin molded body includes a foamed resin molded body having a roughened predetermined surface of the foamed resin molded body itself according to the shape of the above-described mold or the above-described melt-cutting. The body is included.
In addition, the code | symbol in each said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

  According to the first feature of the present invention described above, a foamed resin composite structure having excellent impact resistance can be realized. According to experiments conducted by the inventors of this application, the tensile strength at break is 8 to 8 when the tensile strength is 0.6 to 37 MPa and the film thickness is 500 μm at the use environment temperature of 0 to 60 ° C. The foamed resin composite structure in which 2000% of the resin film is formed on at least the surface opposite to the surface on which the load is applied among the foamed resin base material is a foamed resin base material on which no resin film is formed. The impact resistance was higher than that of the material alone.

  In particular, according to the second feature of the present invention, since the resin film is also formed on the surface to which the load is applied, the impact resistance can be further enhanced.

  As described in the third feature, the resin film described in the first and second features described above is made of at least one of acrylic, synthetic rubber, vinyl acetate, ethylene, epoxy, and urethane. It can be formed by applying a coating material containing at least a solvent type or dispersion type resin to the base material. In particular, since the resin film can be formed on the base material by an easy method of coating, a special film forming apparatus is not required for the production of the foamed resin composite structure. Can be manufactured.

  As described in the fourth feature, the resin film described in the first and second features is a coating material including at least a solvent-free resin composed of at least one of acrylic, epoxy, and urethane. Can be formed by applying to the base material. In particular, since the resin film can be formed on the base material by an easy method of coating, a special film forming apparatus is not required for the production of the foamed resin composite structure. Can be manufactured.

As described in the fifth feature, the resin described in the third or fourth feature can be formed of an acrylic emulsion. That is, if an acrylic emulsion is used, a resin film excellent in tensile strength and tensile breaking elongation can be formed on the base material.
In particular, when an aqueous resin emulsion is used, there are effects that the base material is not dissolved, the occurrence of VOC (Volatile Organic Compounds) is small, and the viscosity can be easily adjusted with water.

  In particular, as described in the sixth feature of the present invention, when a room temperature crosslinking acrylic emulsion is used, a crosslinking reaction is caused at room temperature, and a resin film can be formed on a base material. Therefore, the manufacturing efficiency of the foamed resin composite structure can be increased. Moreover, since the molecular weight of the resin can be easily increased by the crosslinking reaction, the impact resistance of the foamed resin composite structure can be dramatically increased.

  According to the seventh feature of the present invention, a foamed resin composite structure having excellent impact resistance can be produced by applying a coating material in which a plurality of types of resins are mixed to a base material.

  According to the eighth feature of the present invention, the impact resistance can be enhanced by forming a resin film having a glass transition temperature of -30 to 38 ° C.

  According to the ninth feature of the present invention, when the use environment temperature is 5 to 35 ° C., the impact resistance is improved by forming a resin film having a glass transition temperature of −30 to 25 ° C. Can do.

  According to the tenth feature of the present invention, if a resin film having a glass transition temperature of −17 to 20 ° C. is formed, the impact resistance can be enhanced at any of the above environmental temperatures.

Moreover, even if the coating material alone cannot form a resin film having the tensile strength and tensile breaking elongation specified in the first feature described above, as described in the eleventh feature described above, By adding an additive to the coating material, a resin film having the above-described tensile strength and tensile elongation at break can be formed.
The coating material can be changed to fall within the glass transition temperature range.

  Moreover, even if it is a coating material that cannot form a resin film having the tensile strength and tensile breaking elongation specified in the first feature described above alone, as described in the twelfth feature described above, By adding a filler to the coating material, a resin film having the above-described tensile strength and tensile breaking elongation can be formed.

  Further, as described in the thirteenth feature described above, by applying a coating material containing a drug to a base material, the effect of the drug can be given to the coated surface. For example, the base material can be provided with an ant-preventing effect by including an ant-preventing agent in the resin. Further, by incorporating an antibacterial agent into the resin, the base material can have an antibacterial effect. Further, by adding a fungicide to the resin, the base material can have a fungicide effect.

  Further, as described in the fourteenth feature described above, by applying a coating material containing a conductive material to a base material, the coated surface can be made conductive. For example, the base material can be made conductive by adding copper powder, conductive carbon, or the like to the resin.

  Further, as described in the fifteenth feature described above, by applying a coating material containing a magnetic material to a base material, the coated surface can have magnetism. For example, the base material can be magnetized by containing cobalt ferrite magnetic powder in the resin.

  In addition, as described in the sixteenth feature described above, if the thickness of the resin film is at least 50 μm or more, a foamed resin composite structure excellent in impact resistance can be manufactured.

  According to the seventeenth feature described above, since the resin film is in close contact with the base material and can be peeled off from the end of the film, the base material and the resin film are individually provided. Can be disposed of or recycled.

  According to the eighteenth feature described above, since the resin film is configured not to crack even when a load is applied to a surface to which a load is applied and the base material is broken, the broken base material is formed. There is no risk of dispersion. In addition, when the foamed resin composite structure is used as a container, the water-stopping effect is not lost even if the base material is broken, so that the liquid stored in the container does not leak.

  Further, according to the nineteenth feature described above, the surface of the resin film formed on the base material has adhesiveness. Therefore, if the surface is used, the foamed resin composite structure can be obtained without using an adhesive. It can be easily mounted on the mounting target.

  For example, as described in the twentieth feature described above, when the above foamed resin composite structure is used as a cushioning material for a packaging material, if the surface of the base material is attached to a portion on which a load to be packaged is applied, adhesion is achieved. Even without using an agent, a cushioning material is arranged, and a packaging material excellent in impact resistance can be easily manufactured.

It is explanatory drawing which shows the manufacturing process of the foamed resin composite structure which concerns on this invention. It is explanatory drawing when a load is applied to a foamed resin composite structure, (a) shows the positional relationship between the surface on which the load is applied and the surface on which the resin film is formed, and (b) is the foamed resin composite structure. The state which the body deform | transformed is shown, (c) shows the state which the foamed resin composite structure fractured | ruptured. It is explanatory drawing of the resin film which can peel, (a) shows before peeling, (b) shows the time of starting peeling. It is explanatory drawing which shows the state in which the shock absorbing material 50 was attached to the inside of the packing material 60. FIG. It is explanatory drawing which shows the method of attaching the shock absorbing material 50 to the corner of the bottom wall 63, (a) shows before attachment, (b) shows after attachment. It is explanatory drawing of the experimental apparatus used in Experiment 1. FIG. It is the table | surface which put together the experimental data of the experiment using an acrylic emulsion and an epoxy resin as a coating material. It is a graph which shows the impact strength and film thickness characteristic created based on the experimental data of FIG. It is the table | surface which put together the experimental data of the experiment using the blend of acrylic emulsion as a coating material. It is a graph which shows the impact strength and film thickness characteristic created based on the experimental data of FIG. It is the table | surface which put together the experimental data of the experiment using what added the film-forming aid to the acrylic emulsion as a coating material. It is a graph which shows the impact strength and film thickness characteristic produced based on the experimental data of FIG. It is a component table | surface of the coating material which added the film-forming aid and the filler to the acrylic emulsion. It is the table | surface which put together the experimental data of the experiment using the coating material which added the film-forming adjuvant and the filler to acrylic emulsion. It is a graph which shows the impact strength and film thickness characteristic produced based on the experimental data of FIG. It is the table | surface which put together the experimental data in the impact strength test under environmental temperature 0 degreeC. It is a graph which shows the impact strength and film thickness characteristic created based on the experimental data of FIG. It is the table | surface which put together the experimental data in the impact strength test under environmental temperature 5 degreeC. It is a graph which shows the impact strength and film thickness characteristic produced based on the experimental data of FIG. It is the table | surface which put together the experimental data in the impact strength test under environmental temperature 35 degreeC. It is a graph which shows the impact strength and film thickness characteristic produced based on the experimental data of FIG. It is the table | surface which put together the experimental data in the impact strength test under environmental temperature 60 degreeC. It is a graph which shows the impact strength and film thickness characteristic produced based on the experimental data of FIG. 10 is a table summarizing the measurement results of Experiment 2. 10 is a table summarizing the measurement results of Experiment 3. 10 is a table summarizing the measurement results of Experiment 4. It is a graph which shows the impact strength and film thickness characteristic created based on the experimental data of FIG. It is the table | surface which put together the result of Experiment 1-5, and put together the evaluation result of the impact absorption effect of each resin film in the use environment temperature of 0-60 degreeC. 10 is a table summarizing the results of Experiment 6. It is explanatory drawing when a load is applied to the conventional foamed resin composite structure, (a) is a longitudinal cross-sectional view of a foamed resin composite structure, (b) is explanatory drawing of the application direction of a load, (c ) Is a longitudinal sectional view of a destroyed foamed resin composite structure.

  An embodiment of a foamed resin composite structure according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a manufacturing process of a foamed resin composite structure according to the present invention. In this embodiment, a cushioning material will be described as an example of the foamed resin composite structure according to the present invention.

[Method of manufacturing cushioning material]
First, as shown in FIG. 1A, a base material 51 for forming a buffer material 50 is prepared. The base material 51 used in this embodiment is a foamed resin molded product formed of a beaded polystyrene foam (Expandable Poly-Styrene: hereinafter abbreviated as EPS). Further, the expansion ratio is a relatively high expansion ratio such as 38 times, 60 times, and 90 times, and the weight is reduced. In the figure, the surface denoted by reference numeral 51a is the surface on which the main load is applied, and the surface denoted by reference numeral 51b is the back surface that is the surface opposite to the surface on which the main load is applied.

  Next, as shown in FIG. 1B, a resinous coating material 52 is applied to the back surface 51 b of the base material 51. The coating thickness is at least 50 μm or more. The coating method may be brush coating or coating using a roller, and is not particularly limited. In this embodiment, a room temperature cross-linked acrylic emulsion paint is used as a paint because it can be formed at room temperature and is excellent in tensile strength and tensile breaking elongation after film formation.

  Next, as shown in FIG. 1C, the coating material 52 is dried to form a resin film 53 on the back surface 51 b of the base material 51. The drying method of the coating material 52 may be natural drying or forced drying by heating. For example, the film can be efficiently formed by leaving it to dry in a drying room at 60 ° C. for 3 hours.

The resin film 53 has a tensile strength of 0.6 to 37 MPa under a use environment temperature of 0 to 60 ° C., and has a tensile fracture elongation of 8 to 2000% when the film thickness is 500 μm (each numerical value). The reason for this will be described later). Therefore, as shown in FIG. 2A, even when the load F1 is applied to the surface 51a of the cushioning material 50 and the base material 51 is rapidly deformed, as shown in FIG. Since the resin film 53 is deformed following the base material 51 and is not easily broken, the base material 51 is not easily broken. Further, as shown in FIG. 2C, even when a load F2 larger than the load F1 is applied and the base material 51 is broken, the resin film 53 is not easily broken, so that an impact due to the load F2 is applied. It can be absorbed by the resin film 53.
Therefore, the shock resistance of the cushioning material 50 can be improved as compared with the conventional case.

  The resin film 53 is in close contact with the back surface 51b of the base material 51 so as to be peelable. For this reason, as shown in FIG. 3B, when the end portion of the resin film 53 is picked and pulled in the direction of the arrow, the surface layer of the foamed resin or the vicinity of the surface of the foamed layer is destroyed from the back surface 51b of the base material 51. Can be peeled off. For this reason, when the buffer material 50 is discarded or recycled, it can be disposed of or separated into the base material 51 and the resin film 53.

  Furthermore, since the surface of the resin film 53 has an adhesive force under the usage environment temperature, the cushioning material 50 can be attached to a predetermined location without using an adhesive. FIG. 4 is an explanatory view showing a state in which the cushioning material 50 is attached inside the packing material 60. The packing material 60 is formed in a box shape from corrugated cardboard or resin, and includes four side walls 61, four lid members 62, and one bottom wall 63. The shock absorbing material 50 is attached to the four corners of the bottom wall 63.

  FIG. 5 is an explanatory view showing a method of attaching the cushioning material 50 to the corner of the bottom wall 63. As shown in FIG. 6A, the cushioning material 50 is pressed against the corner of the bottom wall 63 with the resin film 53 facing downward, and is attached using the adhesive force of the resin film 53. As described above, since the cushioning material 50 can be attached to the packaging material 60 without using an adhesive, the mounting work efficiency of the cushioning material 50 can be increased, and the manufacturing cost of the packaging material 60 can be reduced. be able to.

  Further, since the resin film 53 is detachably attached to the bottom wall 63, the cushioning material 50 can be peeled off from the bottom wall 63. Therefore, when the packaging material 60 is disposed, the buffer material 50 can be separated and disposed or recycled. At this time, since the resin film 53 can be peeled off from the base material 51 as described above, the resin film 53 can also be separated and discarded or recycled.

[Experiment 1]
The inventors of this application conducted an experiment to examine the impact resistance of the foamed resin composite structure. This experiment was conducted according to the method and apparatus defined in JIS K7211 of Japanese Industrial Standard. FIG. 6 is an explanatory diagram of the apparatus.

  In this experiment, the effects of the tensile strength and tensile breaking elongation of the resin film on the impact resistance of the foamed resin composite structure were investigated. The relationship between the glass transition temperature of the coating material and the impact resistance was also investigated. First, coating materials having different properties were applied to the base material to prepare test pieces on which resin films having different properties were formed. The test piece coated with the coating material was dried by curing at 60 ° C. for 5 hours.

(Acrylic emulsion and epoxy resin)
Six types of coating materials made of acrylic emulsion and three types of coating materials made of epoxy resin were prepared. Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of nine types of test pieces 50 having different properties of the resin film 53 were created.

  Coating material 1 (2720D) is an acrylic styrene aqueous emulsion of a one-component room temperature crosslinkable compound, having a resin solid content of 48% by weight, a film forming temperature of 6 ° C., and a glass transition temperature Tg of 9 ° C. 2720D is an abbreviation for the product name Acronal YJ2720D (Acronal is a registered trademark of BASF Japan) manufactured by BASF Japan.

  Coating material 2 (1655D) is an acrylic styrene-based aqueous emulsion having a resin solid content of 56% by weight, a film forming temperature of 7 ° C., and a glass transition temperature Tg of 6 ° C. Also, 1655D is an abbreviation for the product name Acronal YJ1655D of BASF Japan.

  The coating material 3 (S400) is an aqueous emulsion of an acrylate-styrene copolymer resin, the resin solid content is 57% by weight, the film forming temperature is less than 0 ° C, and the glass transition temperature Tg is -7 ° C. S400 is an abbreviation for the product name Acronal S400 of BASF Japan.

  Coating material 4 (2716D) is an aqueous emulsion of an acrylate-styrene copolymer, the resin solid content is 48% by weight, the film forming temperature is 24 ° C., and the glass transition temperature Tg is 25 ° C. 2716D is an abbreviation for the product name Acronal YJ2716D of BASF Japan.

  Coating material 5 (80DN) is an aqueous emulsion composed of an acrylate-acrylonitrile copolymer, the resin solid content is 50% by weight, the film forming temperature is less than 0 ° C., and the glass transition temperature Tg is −47 ° C. 80DN is an abbreviation for the product name Acronal 80DN of BASF Japan.

  The coating material 6 (801N / F51) is an epoxy resin having a solid content of 100% by weight, and the glass transition temperature Tg is 30 ° C. The coating material 7 (801N / ST12) is an epoxy resin having a solid content of 100% by weight, and the glass transition temperature Tg is 70 ° C. The coating material 8 (814 / FL240) is an epoxy resin having a solid content of 100% by weight, and has a glass transition temperature Tg of less than 0 ° C. 801N / F51, 801N / ST12 and 814 / FL240 are product names of Japan Epoxy Resin Co., Ltd.

  The coating material 2755D was not added to the test because it had a poor film formation. 2755D is an aqueous emulsion of an acrylic ester-acrylonitrile copolymer 1 liquid room temperature crosslinkable compound, and the glass transition temperature Tg is 43 ° C. 2755D is an abbreviation for the product name Acronal YJ2755D of BASF Japan.

(Impact strength test)
The inventors of this application conducted a test to examine the strength of the foamed resin composite structure against impact (hereinafter referred to as impact strength). The base material of the test piece 50 used in this test is a foamed resin molded body having an expansion ratio of 60 times. A resin film 53 is formed on the back surface of the test piece 50. The size of the test piece 50 is 150 mm × 150 mm × thickness 15 mm. The mass of the steel ball 71 is 500 g. The interval W between the inner surfaces of the test table 70 when the test piece 50 is placed on the test tables 70, 70 is 80 mm. The environmental temperature of the test is 23 ° C.

  Then, the steel ball 71 is dropped on the surface 51a of the test piece 50 placed on the test stand 70, and half of the ten test pieces are destroyed, and the drop height of the steel ball 71 when half is not destroyed. (50% fracture height) was measured. In addition, the fracture energy at 50% fracture height was calculated. The coating material was applied once, twice and three times to gradually increase the thickness of the resin film 53, and the 50% fracture height at each thickness was measured to calculate the fracture energy.

  FIG. 7 is a table summarizing experimental data, and FIG. 8 is a graph showing impact strength / film thickness characteristics created based on the experimental data of FIG. The 50% fracture height of the conventional product in which the resin film was not formed was 4 cm. As shown in the figure, if each test piece on which the resin films of coating materials 1 to 8 are formed has a resin film of at least 50 μm, the 50% fracture height becomes higher than 4 cm of the conventional product, and impact It turned out that intensity became high. It was also found that each test piece had higher impact strength as the resin film became thicker.

  Among the test pieces, particularly, the test piece in which the resin film was formed with the coating material 1 (2720D) or the coating material 2 (1655D) had a high rate of increase in impact strength with respect to the increase in the thickness of the resin film. That is, the increase in the thickness of the resin film effectively improved the impact strength. In addition, the test piece in which the resin film is formed with the coating material 8 (epoxy resin C) or the coating material 3 (S400) has a lower rate of increase in impact strength with respect to the increase in the thickness of the resin film than the coating materials 1 and 2, The rate of increase became higher when the film thickness exceeded 100 μm.

  In addition, the test piece in which the resin film is formed with the coating material 4 (2716D) has a lower rate of increase in impact strength with respect to the increase in the film thickness of the resin film than the coating materials 3 and 9, but from the point when the film thickness exceeds 100 μm. The rate of increase in impact strength with increasing film thickness increased. In addition, the test piece in which the resin film was formed of any one of the coating material 5 (80DN), the coating material 6 (epoxy resin A), and the coating material 7 (epoxy resin B) had higher impact strength than the conventional product. Compared with the test piece in which the resin film was formed with other coating materials, the rate of increase in impact strength with respect to the increase in film thickness was low. Further, the glass transition temperatures of the coating materials 1, 2, 3, 4 and 8 having a relatively high rate of increase in impact strength with respect to the increase in film thickness are 9 ° C., 6 ° C., −7 ° C., 25 ° C. and <0 ° C. Since the glass transition temperatures of the coating materials 5, 6 and 7 having relatively low increase rates are −47 ° C., 30 ° C. and 70 ° C., respectively, the glass transition temperatures are −7 ° C. to 25 ° C. It has been found that if the resin film is formed from a coating material within the range, a foamed resin composite structure having excellent impact resistance can be produced.

(Acrylic emulsion blend)
Three types of coating materials were prepared by blending different acrylic emulsions. Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of three types of test pieces 50 having different properties of the resin film 53 were created. Coating materials 10 to 12 are obtained by blending coating material 1 (2720D) and coating material 4 (2716D) in a weight ratio of 2: 1, 1: 1, and 1: 2, respectively.

FIG. 9 is a table summarizing experimental data, and FIG. 10 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. As shown in the drawing, each test piece on which the resin films of the coating materials 10 to 12 are formed has a higher rate of increase in impact strength with respect to the increase in the film thickness of the resin film than the coating material 4 (2716D).
That is, by blending the coating material 1 (2720D) with the coating material 4 (2716D), the impact strength can be efficiently increased with respect to the increase in the film thickness of the resin film.

  Moreover, the glass transition temperature Tg of the coating materials 10-12 is 14 degreeC, 17 degreeC, and 20 degreeC, respectively. That is, by blending acrylic emulsions having different glass transition temperatures, the glass transition temperature in the case of an acrylic emulsion alone can be changed. In the case of the coating materials 10 to 12, the glass transition temperature is higher than 9 ° C. in the case of 2720D alone and lower than 25 ° C. in 2716D alone.

  The glass transition temperatures of 80DN (Coating Material 5) and 2755D are −47 ° C. and 43 ° C., respectively. The glass transition temperature of the coating material obtained by blending 80DN and 2755D at a weight ratio of 1: 1 is −10 It is higher than the case of 80DN alone and lower than the case of 2755D alone (not shown). That is, in one kind of acrylic emulsion, even if the glass transition temperature is outside the glass transition temperature range (−7 ° C. to 25 ° C.) capable of enhancing the impact resistance described above, a plurality of kinds of acrylic emulsions are used. By blending at a predetermined weight ratio, a coating material that falls within the above range can be manufactured. If a resin film is formed from the coating material, a foamed resin composite structure having excellent impact resistance can be manufactured. be able to.

(Acrylic emulsion + film-forming aid)
Six coating materials prepared by adding a film-forming aid to an acrylic emulsion were prepared. Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of six types of test pieces 50 having different properties of the resin film 53 were created. Coating materials 20 to 23 are obtained by adding 1% by weight, 3% by weight, 5% by weight, and 8% by weight of a film-forming auxiliary (texanol) to coating material 1 (2720D). The film forming aid (Texanol) is added to the coating material 4 (2716D) by 1 wt% and 3 wt%, respectively.
Texanol (registered trademark of Eastman Chemical Company) consists of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

  FIG. 11 is a table summarizing experimental data, and FIG. 12 is a graph showing impact strength / film thickness characteristics created based on the experimental data of FIG. As shown in the drawing, the test pieces on which the resin films of the coating materials 20 to 22 were formed had substantially the same rate of increase in impact strength with respect to the increase in the film thickness of the resin film as compared with the coating material 1. On the other hand, the test piece on which the resin film of the coating material 23 was formed had a low rate of increase in impact strength when the resin film thickness exceeded 100 μm. That is, when a film-forming aid is added to the coating material 2720D, the rate of increase in impact strength with respect to an increase in the film thickness of the resin film can be improved by setting the amount of film-forming aid to be less than 8% by weight. it can.

  In addition, each test piece on which the resin films of the coating materials 23 and 24 are formed has a very high rate of increase in impact strength with respect to an increase in the thickness of the resin film, as compared with the coating material 4 (2716D). That is, by adding a film-forming aid to the coating material 4 (2716D), the impact strength can be efficiently increased with respect to the increase in the film thickness of the resin film, compared to the case of the coating material 4 alone.

The glass transition temperatures Tg of the coating materials 20 to 23 are 1 ° C., −8 ° C., −17 ° C., and −30 ° C., respectively, and the glass transition temperatures Tg of the coating materials 24 and 25 are 20 ° C. and 10 ° C., respectively. It is. That is, the glass transition temperature of the acrylic emulsion alone can be changed by adding a film-forming aid to the acrylic emulsion. In the case of coating materials 20 to 23, the glass transition temperature can be lower than 9 ° C. in the case of 2720D alone, and in the case of coating materials 24 and 25, the glass transition temperature is lower than 25 ° C. in the case of 2716D alone. Can be lowered.
The glass transition temperatures of the coating materials 22 and 23 are −17 ° C. and −30 ° C., respectively, and the glass transition temperature range (−7 ° C. to 25 ° C.) in which the above-mentioned acrylic emulsion alone can improve impact resistance. However, if a resin film is formed from the coating material by adding a film-forming aid, a foamed resin composite structure having excellent impact resistance can be produced.

(Acrylic emulsion + film-forming aid + filler)
6 types of coating materials are prepared by adding a film-forming aid and filler to an acrylic emulsion. How the impact resistance of the foamed resin composite structure changes depending on the type and proportion of the film-forming aid and filler to be added. Was tested. In this test, one type of coating material was applied to one test piece 50 to form a resin film 53, and six types of test pieces 50 having different properties of the resin film 53 were created. FIG. 13 is a component table of each coating material. The common mill base components in the coating materials 30 to 33 are 41.5 g of water, 10 g of a dispersant (Pigment Disperser A), 25 g of a thickener (2% QP4400H), 1 g of an antiseptic (actide MBS), an antifoaming agent ( SN deformer 777) 1.5 g, propylene glycol 10 g, PH adjuster (Annsui 28%) 1 g, titanium oxide (JR605) 200 g, super SS (4 micron) 150 g, heavy calcium carbonate (super SS (4 micron)) 150 g , 200 g of heavy calcium carbonate (12 microns).

  Common millbase components in the coating materials 34 and 35 are 20 g of water, 5 g of a dispersant (Pigment Disperser A), 25 g of a thickener (2% QP4400H), 1 g of an antiseptic (actide MBS), and an antifoaming agent (SN deformer). 777) 1.5 g, propylene glycol 10 g, PH adjuster (Annsui 28%) 1 g, and titanium oxide (JR605) 200 g.

  The components of the coating material 30 (B coating material) were 640 g of the above-mentioned mill base, 327.7 g of coating material 1 (2720D), 10 g of a film-forming auxiliary (texanol), and a 90% aqueous solution of 2-amino-2-methyl-1-propanol. (AMP90) 1 g, antifoaming agent (SN deformer 777) 0.5 g, water 20 g. The volume ratio (PVC) of the filler to the resin of the coating material 30, the solid content, the resin content, and the titanium oxide content are 53%, 71 wt%, 16 wt%, and 19 wt%, respectively.

  The components of the coating material 31 (B + 2720D) are 640 g of the mill base, 750 g of the coating material 1 (2720D), 10 g of a film-forming aid (texanol), and a 90% aqueous solution of 2-amino-2-methyl-1-propanol (AMP90). 1 g, 0.5 g of antifoaming agent (SN deformer 777), and 20 g of water. The volume ratio (PVC), solid content, resin content, and titanium oxide content of the filler of the coating material 31 to the resin are 33%, 64 wt%, 25 wt%, and 13 wt%, respectively.

  The components of the coating material 32 (B + 80DN) are 640 g of the above-mentioned mill base, 327.7 g of the coating material 1 (2720D), 400 g of the coating material 5 (80DN), 10 g of a film-forming auxiliary (texanol), 2-amino-2-methyl- 1 g of 90% aqueous solution of propanol (AMP90), 0.5 g of antifoaming agent (SN deformer 777), and 20 g of water. The volume ratio (PVC) of the filler to the resin of the coating material 32, the solid content, the resin content, and the titanium oxide content are 33%, 65 wt%, 11 wt%, and 14 wt%, respectively.

  The components of the coating material 33 (B + S400) were 640 g of the above-mentioned mill base, 327.7 g of coating material 1 (2720D), 350 g of coating material 3 (S400), 10 g of film-forming aid (texanol), 2-amino-2-methyl- 1 g of 90% aqueous solution of propanol (AMP90), 0.5 g of antifoaming agent (SN deformer 777), and 20 g of water. The volume ratio (PVC) of the filler to the resin of the coating material 33, the solid content, the resin content, and the titanium oxide content are 33%, 67 wt%, 12 wt%, and 14 wt%, respectively.

  The components of the coating material 34 (A coating material) were 263.5 g of the above-mentioned mill base, 700 g of coating material 1 (2720D), 21 g of a film-forming aid (texanol), and a 90% aqueous solution of 2-amino-2-methyl-1-propanol. (AMP90) 1 g, antifoaming agent (SN deformer 777) 0.5 g, water 13 g, viscosity modifier (SN thickener 612 / PW = 1/3 (10%)) 0.74 g. The volume ratio (PVC) of filler to resin of the coating material 34, the solid content, the resin content, and the content of titanium oxide are 12%, 54 wt%, 34 wt%, and 20 wt%, respectively.

  The components of the coating material 35 (A + 2720D) were 263.5 g of the above-mentioned mill base, 1800 g of the coating material 1 (2720D), 21 g of a film-forming auxiliary (texanol), and a 90% aqueous solution of 2-amino-2-methyl-1-propanol ( AMP90) 1 g, antifoaming agent (SN deformer 777) 0.5 g, water 13 g, viscosity modifier (SN thickener 612 / PW = 1/3 (10%)) 0.74 g. The volume ratio (PVC) of the filler to the resin of the coating material 34, the solid content, the resin content, and the titanium oxide content are 5%, 51 wt%, 41 wt%, and 10 wt%, respectively.

  FIG. 14 is a table summarizing experimental data, and FIG. 15 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. As shown in the drawing, each test piece on which the resin film of the coating material 30 to 35 is formed has a high rate of increase in impact strength as the resin film thickness increases. In other words, fillers (titanium oxide, heavy calcium carbonate (super SS (4 microns)) and heavy calcium carbonate (12 microns)), dispersants, preservatives, antifoaming agents, pH adjusters, etc. for acrylic emulsions Even in the case of adding, the impact strength could be increased by increasing the thickness of the resin film.

  Moreover, the glass transition temperature of the coating material 32 is −21 ° C., which is outside the glass transition temperature range (−7 ° C. to 25 ° C.) that can improve the impact resistance with the acrylic emulsion alone, By adding a filler and forming a resin film with the coating material, a foamed resin composite structure excellent in impact resistance can be produced.

(Impact strength test at an environmental temperature of 0 ° C)
The inventors of this application conducted a test to examine the impact strength of the foamed resin composite structure at an environmental temperature of 0 ° C. In this test, the coating material 1 (2720D), the coating material 3 (S400), the coating material 4 (2716D), the coating material 5 (80DN), the coating material 12 (2720D: 2716D = 1: 2) and the coating material 23 (2720D +). A total of 6 types of coating materials were prepared (film forming aid 8%). Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of six types of test pieces 50 having different properties of the resin film 53 were created.

  FIG. 16 is a table summarizing experimental data, and FIG. 17 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. 17 and 8, the coating material 3 has a higher impact strength increase rate corresponding to the increase in the film thickness of the resin film 53 when the environmental temperature is 0 ° C. than when the environmental temperature is 23 ° C. Yes. 17 and 12, when the environmental temperature of the coating material 23 is 0 ° C., the rate of increase in impact strength is halfway corresponding to the increase in the film thickness of the resin film 53. It ’s getting high without hitting it.

  The coating materials 1 and 4 have a higher impact strength increase rate corresponding to the increase in the thickness of the resin film 53 when the environmental temperature is 23 ° C. than when the environmental temperature is 0 ° C. Further, comparing FIG. 17 and FIG. 10, the rate of increase in impact strength corresponding to the increase in the film thickness of the resin film 53 is higher in the coating material 12 when the environmental temperature is 23 ° C. than when it is 0 ° C. Further, comparing FIG. 17 and FIG. 8, the coating material 5 has almost no change in characteristics when the environmental temperature is 23 ° C. or 0 ° C.

(Impact strength test at 5 ° C environmental temperature)
The inventors of this application conducted a test to examine the impact strength of the foamed resin composite structure at an environmental temperature of 5 ° C. In this test, coating material 1 (2720D), coating material 3 (S400), coating material 4 (2716D), coating material 5 (80DN), coating material 12 (2720D: 2716D = 1: 2), coating material 23 (2720D +) A total of seven coating materials were prepared: a film-forming auxiliary 8%) and a coating material 26 (2755D + film-forming auxiliary 1%). Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of seven types of test pieces 50 having different properties of the resin film 53 were created.

  18 is a table summarizing experimental data, and FIG. 19 is a graph showing impact strength / film thickness characteristics created based on the experimental data of FIG. Comparing FIG. 19 and FIG. 17, the coating materials 1, 3, 4, 5, and 12 have a slightly lower impact strength increase rate corresponding to the increase in the thickness of the resin film 53 than when the environmental temperature is 0 ° C. It has become. Moreover, the coating material 26 was improved in defective film formation as a result of adding 1% of a film forming aid, and by forming the resin film 53, the impact strength was slightly higher than that of the conventional product.

(Impact strength test at an ambient temperature of 35 ° C)
The inventors of this application conducted a test to examine the impact strength of the foamed resin composite structure at an environmental temperature of 35 ° C. In this test, the coating material 1 (2720D), the coating material 3 (S400), the coating material 4 (2716D), the coating material 5 (80DN), the coating material 23 (2720D + film-forming aid 8%) and the coating material 26 (2755D +). A total of 6 types of coating materials (1%) were prepared. Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of six types of test pieces 50 having different properties of the resin film 53 were created.

  FIG. 20 is a table summarizing experimental data, and FIG. 21 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. Comparing FIG. 21 and FIG. 8, in the coating materials 1 and 3, the rate of increase in impact strength corresponding to the increase in the film thickness of the resin film 53 is slightly lower than when the environmental temperature is 23 ° C. Further, the coating material 4 has a higher impact strength increase rate corresponding to the increase in the thickness of the resin film 53 than when the environmental temperature is 23 ° C. Further, the characteristics of the coating material 5 are hardly changed from those at the environmental temperature of 23 ° C. Further, comparing FIG. 21 and FIG. 12, the characteristics of the coating material 23 are almost the same as when the environmental temperature is 23.degree.

(Impact strength test at 60 ° C environmental temperature)
The inventors of this application conducted a test to examine the impact strength of the foamed resin composite structure at an environmental temperature of 60 ° C. In this test, coating material 1 (2720D), coating material 3 (S400), coating material 4 (2716D), coating material 22 (2720D + film-forming aid 5%), coating material 23 (2720D + film-forming aid 8%) A total of six types of coating materials were prepared: coating material 26 (2755D + film-forming aid 1%). Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of six types of test pieces 50 having different properties of the resin film 53 were created.

  FIG. 22 is a table summarizing experimental data, and FIG. 23 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. Comparing FIG. 23 and FIG. 21, the coating materials 1, 4 and 23 have a lower impact strength increase rate corresponding to the increase in the film thickness of the resin film 53 than when the environmental temperature is 35 ° C. Further, the coating material 26 has a higher impact strength increase rate corresponding to the increase in the thickness of the resin film 53 than when the environmental temperature is 35 ° C. Further, the coating material 22 in which 5% of the film-forming aid is added to 2720D has a higher increase rate than the coating material 23 in which 8% of the same film-forming aid is added to 2720D, and the film thickness of the resin film is higher. Until about 150 μm, the rate of increase is higher than that of the coating material 26 in which 1% of the same film-forming aid is added to 2755D.

[Experiment 2]
The inventors of this application have foamed a structure in which a resin film is formed only on the surface opposite to the surface on which the load of the base material is applied, and a structure in which a resin film is formed on the surface on which the load is applied and on the opposite surface. An experiment was conducted to examine the difference in strength between the resin composite structures. In this experiment, a test for examining the bending strength in addition to the impact strength in Experiment 1 was performed according to the method and apparatus defined in JIS K7221 of the Japanese Industrial Standard. Moreover, the static energy absorption of the test piece was calculated by multiplying the stress, which is the result of the bending strength test, and the amount of deflection.

  In this experiment, the test piece A in which the resin film of the coating material 1 (2720D) is formed only on the back surface (the surface opposite to the surface on which the load is applied) and the test formed on the front surface (the surface on which the load is applied) and the back surface. Piece B was created. The base material of the test piece and the experimental method are the same as in Experiment 1.

  FIG. 24 is a table summarizing the measurement results of Experiment 2. As shown in the table, the stress of the bending strength of the test piece B in which the resin film of the coating material 1 is formed on both the front and back surfaces is 320 kPa, which is higher than 210 kPa of the test piece A formed only on the back surface. In addition, the test piece B has a 50% fracture height in the falling ball impact strength test of 10 cm, which is higher than 8 cm of the test piece A. Further, the test piece B has a 50% fracture energy of 0.52 J, which is larger than 0.40 J of the test piece A. That is, by forming the resin film of the coating material 1 on the surface to which the load of the base material is applied and the surface on the opposite side, the strength can be increased as compared with the structure formed only on the surface on the opposite side of the surface to which the load is applied. .

  Moreover, in this experiment, the test piece C in which the resin film of the coating material 1 (2720D) is formed on the front surface and the resin film of the coating material 4 (2716D) is formed on the back surface, and the coating material 4 (2716D) on the surface. A test piece D in which a resin film was formed and a resin film of coating material 1 (2720D) was formed on the back surface was subjected to a bending strength test. As a result, it was found that the specimen A was higher than the specimen B with respect to the bending strength. That is, the bending strength can be increased according to the combination contents of the coating material applied to the surface on which the load of the base material is applied and the opposite surface.

[Experiment 3]
The inventors of this application conducted an experiment to examine differences in strength and film thickness characteristics of the foamed resin composite structure when the base material had different foaming ratios. In this experiment, a test for examining compressive strength in addition to impact strength and bending strength was performed according to the method and apparatus defined in JIS K7220 of the Japanese Industrial Standard. In addition, in this experiment, in addition to the base material having an expansion ratio of 60 times (EPS 60 times product) used in Experiments 1 and 2, the base material having an expansion ratio of 90 times (EPS 90 times product) and 38 times A base material (EPS 38 times product) was used.

  In addition, three kinds of coating materials, coating material 4 (2716D), coating material 1 (2720D), and coating material 5 (80DN), were used. Then, one type of coating material was applied to one test piece 50 to form a resin film 53, and a total of nine types of test pieces 50 having different properties of the resin film 53 were created.

FIG. 25 is a table summarizing the measurement results of Experiment 3. As shown in the table, regarding the compressive strength, each test piece exhibited substantially the same compressive strength as that of the conventional product even when the coating material was different at the same expansion ratio. Moreover, each test piece showed substantially the same compressive strength as the conventional product even when the expansion ratio was different.
On the other hand, regarding the bending strength and impact strength, all the test pieces showed higher strength than the conventional products.
In other words, regardless of the foaming ratio of the base material, by forming the resin film according to the present invention on the surface opposite to the surface on which the base material is loaded, the foamed resin composite has higher impact strength and bending strength than the conventional product. A structure can be manufactured. Even when a base material impregnated with various resins at the particle interface was used, the same effect as in the case of the above base material was confirmed.

[Experiment 4]
Next, the inventors changed the properties of the base material and conducted an experiment for examining the change in impact strength accompanying an increase in the thickness of the resin film. In this experiment, a base material having an expansion ratio of 36 times (EPS 36 times product) and an XPS (extruded polystyrene foam) base material having an expansion ratio of 33 times (XPS 33 times product) were used. Moreover, the test piece by which the resin film by the coating material 1 (2720D) was formed in the back surface of EPS36 times product, and the test piece by which the resin film by the coating material 4 (2716D) was formed were produced. Moreover, the film thickness of the resin film was increased by repeating the number of coatings.

  26 is a table summarizing the measurement results of Experiment 4, and FIG. 27 is a graph showing the impact strength / film thickness characteristics created based on the experimental data of FIG. As shown in the graph, the impact strength of the test piece in which the resin film made of the coating material 1 was formed on the back surface of the base material of the EPS 36-fold product increased as the resin film thickness increased. Further, the test piece on which the resin film made of the coating material 4 was formed also increased in impact strength as the resin film thickness increased.

Further, the test piece in which the resin film made of the coating material 1 was formed on the back surface of the base material of the XPS 33-fold product also increased in impact strength as the resin film thickness increased. Further, the test piece on which the resin film made of the coating material 4 was formed also had higher impact strength as the resin film thickness increased.
That is, even if the properties of the base material are different, the impact strength of the base material can be increased by forming the resin film according to the present invention on the back surface of the base material.

[Experiment 5]
In addition, the inventors of this application conducted an experiment to examine the tensile strength and tensile breaking elongation of the resin film. This experiment was conducted according to the method and apparatus defined in JISK7113 of the Japanese Industrial Standard. The test piece (resin film) is a No. 2 type test piece specified in JIS, and its film thickness is 500 μm. The measurement results are shown in FIG.

[Summary]
The impact absorption effect of each resin film was evaluated based on the results of Experiments 1-5. FIG. 28 is a table summarizing the evaluation results. "○" in the table indicates the result of evaluating that the foamed resin composite structure formed by the coating material is more practical than the conventional product when it is used at the ambient temperature, and that it is practical. “X” indicates a result of evaluation that the impact absorption effect is small and is not practical. The coating material 36 in the table is obtained by mixing the coating material 5 (80DN) and the coating material 3 (S400) at a weight ratio of 2: 3.

  For example, in the graph of impact strength and film thickness characteristics at an environmental temperature of 23 ° C. shown in FIG. 8, the resin films formed by the coating materials 1 to 4 and 8 each have a 50% fracture height as the film thickness increases. Since the rate of increase was high, the product was evaluated as having an impact absorbing effect and marked with “◯”. On the other hand, the resin film formed by the coating material 5 has a very small increase rate compared to the other coating materials 1 to 4 and 8, and therefore, it is evaluated that the impact absorbing effect is small. I attached. In addition, “-” in the table indicates that the experiment was not performed, and “-(◯)” indicates that the experiment was not performed, but the evaluation result of the coating material on both sides in the table was “◯”. The experiment results indicate that the evaluation result is estimated to be “◯”.

In the table, the coating materials are arranged from the left in order of increasing glass transition temperature. From this table, the coating materials with an evaluation “x” for the impact absorbing effect at any environmental temperature are coating material 80DN having a glass transition temperature of −47 ° C. and coating material 2755D having a 43 ° C.
That is, when the use environment temperature is 0 to 60 ° C., the evaluation result is “◯” from among the coating materials whose glass transition temperatures except −47 ° C. and 43 ° C. are in the range of −30 to 38 ° C. If a material is selected and the coating material is applied to the base material, a shock-absorbing material having excellent impact resistance can be manufactured.

  In addition, when the use environment temperature was a normal temperature of 5 to 35 ° C., all the coating materials having a glass transition temperature in the range of −30 to 25 ° C. were evaluated as “◯”. Therefore, when the use environment temperature is a normal temperature of 5 to 35 ° C., if a coating material having a glass transition temperature in the range of −30 to 25 ° C. is selected and the coating material is applied to the base material, the impact resistance Can be manufactured.

  Furthermore, the evaluation result of the coating material having a glass transition temperature of −17 to 20 ° C. was “◯” at any temperature of the use environment temperature of 0 to 60 ° C. Therefore, if a coating material having a glass transition temperature of −17 to 20 ° C. is selected and the coating material is applied to the base material, a shock-absorbing material having excellent impact resistance can be produced at a use environment temperature of 0 to 60 ° C. it can.

In addition, the resin film formed by the coating material 23 having a glass transition temperature of −30 ° C. (2720D + film-forming auxiliary 8%) has a tensile strength of 0.6 MPa (in the table, “ The tensile strength increases as the glass transition temperature increases. The resin film formed of the coating material 12 (2720D + 2716D = 1: 2) having a glass transition temperature of 0 ° C. exhibits a tensile strength of 37 MPa when the use environment temperature is 0 ° C. That is, it was found that the tensile strength of the resin film formed of the coating material within the range of the glass transition temperature of −30 to 38 ° C. is 0.6 to 37 MPa.
Since the tensile strength is a numerical value per unit area of 1 mm 2, the tensile strength shown in FIG. 28 can be obtained even when the film thickness is 50 μm regardless of the film thickness of the resin film.

  In the coating material having a glass transition temperature of −30 to 38 ° C. and an evaluation result of “◯”, the tensile fracture elongation (described as “resin film elongation” in the table) is the smallest. It was 8% of the coating material 4 (2716D) at the time. The tensile elongation at break was the largest in 2,000% of the coating material 36 (80DN + S400 = 2: 3) when the use environment temperature was 23 ° C. That is, it was found that the tensile fracture elongation of the resin film formed of the coating material within the range of the glass transition temperature of −30 to 38 ° C. is 8 to 2,000%.

From the results of the above tensile strength and tensile breaking elongation, a resin film having a tensile strength of 0.6 to 37 MPa and a tensile breaking elongation of 8 to 2,000% at a film thickness of 500 μm is formed on the base material. It was found that a shock-absorbing material having excellent impact resistance can be produced.
Actually, from the coating materials having a glass transition temperature of −30 to 38 ° C., a coating material having an evaluation result of “◯” is selected according to the use environment temperature, and a resin film is formed by the coating material. Thus, it is possible to manufacture a cushioning material having excellent impact resistance.

  In addition, it is an acrylic emulsion which is not described in the table | surface of FIG. 28, and it has a tensile strength of 0.6-37 MPa by itself, and has a tensile fracture elongation of 8-2,000% at a film thickness of 500 μm. Even if the resin film cannot be formed, as described above, a resin film having the above-described tensile strength and tensile elongation can be formed by blending a plurality of types of acrylic emulsions. A coating material can be created.

  For example, the above-mentioned coating material 5 (80DN) alone has a tensile strength at a use environment temperature of 23 ° C. of 0.4 MPa, which is smaller than 0.6 MPa, but the coating material 5 and the coating material 3 (S400) are two: In the coating material 36 mixed at a weight ratio of 3, the tensile strength at a use environment temperature of 23 ° C. was improved to 0.7 MPa, and the evaluation result was “◯”.

  Further, it is a coating material obtained by adding an additive or filler to an acrylic emulsion or the like and is not described in the table of FIG. 28, has a tensile strength of 0.6 to 37 MPa, and has a tensile strength of 8 to Even if it is not possible to form a resin film having a tensile elongation at break of 2,000%, as described above, by adjusting the type and mixing ratio of additives and fillers, the above tensile strength and A coating material capable of forming a resin film exhibiting tensile fracture elongation can be produced.

As described above, various coating materials for producing the cushioning material according to this embodiment can be considered, but the tensile strength is 0.6 to 37 MPa, and the coating material is 8 to 8 at a film thickness of 500 μm. Any coating material can be used as long as it can form a resin film having a tensile fracture elongation of 2,000%.
When such a coating material is selected based on the glass transition temperature, the glass transition temperature is in the range of -30 to 38 ° C, preferably -30 to 25 ° C, more preferably -17 to 20 ° C. If a coating material inside is selected, there is a high possibility that a resin film having the above-described tensile strength and tensile elongation at break can be formed.

[Experiment 6]
The inventors of this application conducted a test for examining the adhesion of the resin film formed on the base material in accordance with the method and apparatus defined in JIS K5600-5-7 of the Japanese Industrial Standard. A test piece having an expansion ratio of 60 times (EPS 60 times), a 90-times test piece (EPS 90 times), and a 15-times test piece (EPS 15 times) were used. And 1 type of coating material was apply | coated per test piece, and the adhesiveness of the resin film formed after drying was investigated.

  The coating material applied to the test specimen of EPS 60 times is coating material 1 (2720D), coating material 4 (2716D), coating material 3 (S400), coating material 5 (80DN), coating material 34 (A paint), coating material. Eight types of coating material 30 (A + 2720D), coating material 30 (B coating material) and coating material 31 (B + 2720D), and coating materials applied to the test piece of EPS 90 times are coating material 1 (2720D) and coating material 4 (2716D). And coating material 5 (80DN), and the coating material applied to the test piece of 15 times EPS is coating material 1 (2720D), coating material 4 (2716D), and coating material 5 (80DN). .

  FIG. 29 is a table summarizing the results of Experiment 6. The symbol A in the table indicates the result of the cohesive failure of the base material. That is, the result shows that the resin film is peeled off due to the cohesive failure of the surface layer of the base material on which the resin film was formed. Symbol A / B indicates the result of adhesion failure between the base material and the resin film. As shown in FIG. 29, the base material cohesively fractured the test piece of EPS 60 times and the test piece of EPS 90 times in any resin film. In the case of the test specimen of 15 times EPS, the base material cohesively fractured in the case of the coating materials 1 and 4, and in the case of the coating material 5, the base material and the resin film adhered and fractured.

  Moreover, the breaking strength of each resin film is 0.3 to 0.4 MPa in the test piece of EPS 60 times, 0.2 to 0.3 MPa in the test piece of EPS 90 times, and 0 in the test piece of EPS 15 times. .3 to 1.4 MPa. Moreover, the resin film formed in each test piece was able to be peeled by picking one end by hand and pulling in the other end direction.

As described above, when each of the above coating materials is applied, even if the base material has a high expansion ratio of 60 times or 90 times, a resin film having a high adhesive force to the base material and capable of being peeled is formed. A foamed resin composite structure can be produced.
In addition, since the surface of each resin film is sticky, when using a foamed resin composite structure as a buffer material, if the resin film surface is pressed against the site where the buffer material is placed, the resin film surface is pasted as a buffer material. Can be worn.

[Other Embodiments]
(1) In the above-described embodiment, an acrylic aqueous emulsion or epoxy system is used as a coating material. However, the coating material is composed of at least one of an acrylic system, a synthetic rubber system, a vinyl acetate system, an ethylene system, an epoxy system, and a urethane system. Solvent-type or dispersion-type resins can also be used.
For example, acrylic solvent-type or dispersion-type resins include butyl acrylate-methyl methacrylate-acrylic acid copolymer, ethyl acrylate-styrene-acrylamide copolymer, 2-ethylhexyl acrylate-methacrylic acid-acrylic acid copolymer. A polymer or the like can be used. As the synthetic rubber solvent type or dispersion type resin, styrene-butadiene latex, styrene-acrylonitrile-butadiene latex, polybutadiene latex, or the like can be used.

  In addition, vinyl acetate, solvent-type or dispersion-type resins include polyvinyl acetate, vinyl acetate-ethyl acrylate copolymer, vinyl acetate-methyl methacrylate copolymer, vinyl acetate-veova copolymer, polyvinyl Alcohol or the like can be used. Also, polyethylene emulsion, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-acrylic acid copolymer, ethylene-acrylonitrile-vinyl acetate copolymer, etc. should be used as ethylene-based solvent-type or dispersion-type resins. Can do.

  In addition, epoxy, butyl acrylate-glycidyl methacrylate-acrylamide copolymer, or the like can be used as an epoxy-based solvent-type or dispersion-type resin. In addition, polyurethane, urethane-modified acrylic acid-methacrylic acid copolymer, or the like can be used as the urethane-based solvent-type or dispersion-type resin.

Furthermore, various resin aqueous emulsions obtained by dispersing each of the above resins in water can be used. For example, an aqueous resin emulsion such as an epoxy resin aqueous emulsion, an ethylene-acrylic acid copolymer resin aqueous emulsion, a modified aliphatic polyamine resin aqueous emulsion, and a biodegradable resin aqueous emulsion can be used.
In particular, when an aqueous resin emulsion is used, there are effects that the base material is not dissolved, the occurrence of VOC (Volatile Organic Compounds) is small, and the viscosity can be easily adjusted with water.

(2) Further, as a coating material, a solventless resin composed of at least one of acrylic, epoxy, and urethane can be used. If these solvent-free resins are used, there is no environmental pollution and safety is high. Moreover, since there is no solvent component which volatilizes, a recessed part is hard to be formed in the film surface after drying.
In particular, when a room temperature crosslinkable acrylic emulsion is used as a coating material, a crosslinking reaction is performed at room temperature, so that a process such as heating is not necessary, and thus manufacturing efficiency can be increased.

(3) Moreover, the foaming resin composite structure in which the coating material containing a chemical | medical agent is apply | coated to a base material, and the resin film containing a chemical | medical agent was formed can also be manufactured. For example, an insecticide such as an antifungal agent, an antibacterial agent, an antifungal agent or the like can be contained as a drug. By forming a resin film containing at least one of these on a base material, a foamed resin composite structure having a drug effect can be produced.

(4) A foamed resin composite structure in which a resin film containing a conductive material is formed by applying a coating material containing a conductive material to a base material can also be manufactured. For example, as a conductive material, gold, silver, copper, nickel, palladium, platinum, cobalt, rhodium, iridium, iron, ruthenium, osmium, aluminum, zinc, tin, lead, or the like in the form of particles, the above metal Even if the alloy is made into particles, metal oxide such as tin oxide is made into particles, or conductive carbon allotrope such as carbon is made into particles, the surface of particles such as glass, carbon, mica, plastic, etc. A material coated with a conductive metal can be used. By forming a resin film containing at least one of these on the base material, a foamed resin composite structure having conductivity can be manufactured.

(5) A foamed resin composite structure in which a resin film containing a magnetic material is formed by applying a coating material containing a magnetic material to a base material can also be produced. For example, as a magnetic material, a powdered cobalt ferrite magnetic material, metal magnetic material, CrO2, γ-Fe2O3, Fe4N, Ba ferrite or the like can be used. By forming a resin film containing at least one of these on the base material, a foamed resin composite structure having magnetism can be produced.

(6) A foamed resin composite structure in which a resin film containing a heat conductive material is formed by applying a coating material containing a heat conductive material to a base material can also be manufactured. For example, copper, aluminum, beryllia, aluminum nitride, boron nitride, alumina, magnesia, titania, diamond, lead, zircon, or the like in powder form can be used as the heat conductive material. By forming a resin film containing at least one of these on the base material, a foamed resin composite structure having high thermal conductivity can be manufactured.

(7) A foamed resin composite structure in which a coating film containing an antistatic agent is applied to a base material to form a resin film containing the antistatic agent can also be produced. For example, as an antistatic agent, non-poly (oxyethylene) alkylamine, poly (oxyethylene) alkylamide, poly (oxyethylene) alkyl ether, poly (oxyethylene) alkylphenyl ether, glycerin fatty acid ester, sorbitan fatty acid ester, etc. Anionic antistatic agents such as ionic antistatic agents; alkyl sulfonates, alkyl benzene sulfonates, alkyl sulfates and alkyl phosphates; cationic antistatic agents such as quaternary ammonium chlorides, quaternary ammonium sulfates and quaternary ammonium nitrates ; Amphoteric antistatic agents such as alkylbetaine type, alkylimidazoline type and alkylalanine type; Conductive resins such as polyvinylbenzyl type cation and polyacrylic acid type cation Etc. can be used. By forming a resin film containing at least one of these on a base material, a foamed resin composite structure having a high antistatic effect can be produced.

The foamed resin composite structure according to the present invention is included in packaging materials for household electrical appliances such as televisions, refrigerators, washing machines, personal computers and peripheral devices, audio and visual products, and other items that need to cushion the load. It can be used as a cushioning material.
Moreover, the helmet excellent in impact resistance can be implement | achieved by applying to the foaming resin molded product provided in the inside of a helmet. Furthermore, if it is used as a cushioning material that cushions an impact load applied to an occupant, such as a door lining of a passenger car, safety can be improved.
Furthermore, if it is applied to a fish box or the like, cracks due to load are less likely to occur, so a fish box having a high water leakage prevention effect can be realized.

  50..Buffer material, 51..Base material, 52..Coating material, 53: Resin film.

Claims (20)

  Among the base materials made of foamed resin, a resin film having a tensile strength of 0.6 to 37 MPa at a use environment temperature of 0 to 60 ° C. and a tensile fracture elongation of 8 to 2000% when the film thickness is 500 μm, A foamed resin composite structure characterized by being formed on at least a surface opposite to a surface to which a load is applied.   The foamed resin composite structure according to claim 1, wherein the resin film is also formed on a surface to which the load is applied.   The resin film is formed by applying a coating material containing at least a solvent type or dispersion type resin composed of at least one of acrylic, synthetic rubber, vinyl acetate, ethylene, epoxy, and urethane to the base material. The foamed resin composite structure according to claim 1, wherein the foamed resin composite structure is formed by:   The resin film is formed by applying a coating material containing at least a solvent-free resin composed of at least one of acrylic, epoxy, and urethane to the base material. The foamed resin composite structure according to any one of claims 1 to 3.   The foamed resin composite structure according to claim 3 or 4, wherein the resin is an acrylic emulsion.   The foamed resin composite structure according to claim 5, wherein the resin is a room temperature crosslinking acrylic emulsion.   The foamed resin composite structure according to any one of claims 3 to 6, wherein the coating material is a mixture of at least a plurality of types of resins.   The foamed resin composite structure according to any one of claims 1 to 7, wherein a glass transition temperature of the resin film is -30 to 38 ° C.   9. The foamed resin composite structure according to claim 8, wherein the resin film has a glass transition temperature of −30 to 25 ° C. and a use environment temperature of 5 to 35 ° C.   The foamed resin composite structure according to claim 9, wherein the glass transition temperature is -17 to 20 ° C.   The foamed resin according to any one of claims 8 to 10, wherein the coating material is a resin having a glass transition temperature outside the range of the glass transition temperature and containing an additive. Composite structure.   The foamed resin composite structure according to any one of claims 3 to 11, wherein the coating material contains a filler in a resin.   The foamed resin composite structure according to any one of claims 3 to 12, wherein the coating material contains a drug.   The foamed resin composite structure according to any one of claims 3 to 13, wherein the coating material contains a conductive material.   The foamed resin composite structure according to any one of claims 3 to 14, wherein the coating material contains a magnetic material.   The foamed resin composite structure according to any one of claims 1 to 15, wherein a thickness of the resin film is at least 50 µm or more.   The foamed resin composite according to any one of claims 1 to 16, wherein the resin film is in close contact with the base material and can be peeled off from an end portion. Structure.   18. The resin film according to any one of claims 1 to 17, wherein the resin film is configured not to crack even when the surface to which the load is applied is loaded and the base material is broken. The foamed resin composite structure described in 1.   The foamed resin composite structure according to any one of claims 1 to 18, wherein a surface of the resin film formed on the base material has adhesiveness.   A packaging material in which the foamed resin composite structure according to claim 19 is disposed as a cushioning material, wherein the surface of the resin film formed on the base material is a portion of the inner surface of the packaging material body on which a load to be packaged is applied. A packing material, wherein the foamed resin composite structure is disposed by sticking to a foam.

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