Resin compositions, heat-expandable molded articles, heat-expandable sheets, and building components.

Abstract

A resin composition in which both the expansion volume and adhesive strength, two conflicting properties in a thermally expandable material, are in good condition; a thermally expandable molded product or thermally expandable sheet formed from the resin composition; and a building component using these that has excellent fire spread prevention effects. [Solution] A resin composition characterized by containing a metal phosphate protonated monoamine storage material in which the metal is a divalent metal, a resin component, and thermally expandable graphite; in particular, a resin composition in which the metal phosphate protonated monoamine storage material is an ammonium metal phosphate; further, the above resin composition in which the ammonium metal phosphate is substantially represented by the structural formula (NH4)2M2P2O8 (where M is a divalent metal); thermally expandable molded articles and thermally expandable sheets formed from the resin composition; and building components utilizing these.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a thermally expandable molded article and a thermally expandable sheet formed from the resin composition, and further to a fitting to which the thermally expandable molded article and the thermally expandable sheet are applied. [Background Art]

[0002] A resin composition containing thermally expandable graphite is molded into, for example, molded articles, sheets, and the like, and these products are used as members of fittings that require a fire spread preventing effect in the event of a fire. For example, it is said that attaching the above product as a member for a frame portion of a window sash contributes to exhibiting a fire spread preventing effect. That is, for a member made of a resin composition containing thermally expandable graphite attached to a window portion of a window sash, the thermally expandable graphite rapidly starts expanding when a fire occurs, and the thermally expanded body oozes out from the frame portion of the window sash, thereby effectively preventing flames from penetrating outward through the window sash, which requires a function (flame penetration preventing effect).

[0003] For the thermally expanded body that rapidly forms in the event of fire as described above, the larger the expansion volume, and the greater the strength (caking strength) of the thermally expanded body to prevent the thermally expanded body from being blown away by the wind force of the fire, the higher the flame penetration preventing effect. To enhance this effect, a flame retardant is used in the resin composition components. As flame retardants, phosphorus compounds, for example, red phosphorus, phosphates such as triphenyl phosphate, tricresyl phosphate, various metal phosphates and ammonium polyphosphate are used. Metal hydroxides are also used. For example, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like are used. Inorganic fillers that act as aggregates are also used to improve the caking strength of the thermally expanded body. For example, titanium oxide, zinc oxide, alumina and the like are used as various metal oxides. Similarly, inorganic substances such as glass fibers, glass beads, and carbon fibers that act as aggregates in the thermally expanded body are also used. Halogenated flame retardants such as tetrabisphenol A, decabromodiphenyl oxide, and chlorinated paraffin are also used.

[0004] However, halogenated flame retardants are undesirable because they release harmful halogen gases during combustion. While inorganic flame retardants emit low levels of harmful gases, our studies have shown they do not significantly contribute to the expansion properties of resin compositions containing thermally expandable graphite. Red phosphorus and various phosphates are effective, but their effects are unsatisfactory. Glass fibers and carbon fibers can be used as composites in sheets, but they present another problem as components of resin compositions: they are difficult to mix. Hydroxides have the effect of temporarily lowering the ambient temperature by releasing water during a fire, but they do not contribute to improving expansion properties.

[0005] As will be discussed later, various resin compositions containing thermally expandable graphite have been proposed and are in use (Patent Documents 1-7, Non-Patent Documents 1-6). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6999102 [Patent Document 2] Patent No. 6225287 [Patent Document 3] Patent No. 5992589 [Patent Document 4] Patent No. 6737761 [Patent Document 5] Patent No. 3505836 [Patent Document 6] Patent No. 3744045 [Patent Document 7] Patent No. 6830609 [Non-patent literature]

[0007] [Non-Patent Document 1] WTAHariison and L.Hannoman Angew.Chem.IntEd.Enngl 36.640(1997) [Non-Patent Document 2] T.Song.MBHursthouse..J.Chem.Adv.Mater.6.679(1994) [Non-Patent Document 3] D.Chidambaram and S.Natarajan.Materials.Bulletin.Vol.33.No8.P1275(1998) [Non-Patent Document 4] Kataoka, Itaya, Kinoshita, Journal of the Ceramics Association 93 "10", pp. 606-611 (1985) [Non-Patent Document 5] Jiesheng Chen, RichardH, Angew.Chem.Ed.Engl Vol33 No6 P639(1994) [Non-Patent Document 6] Pingyunn Fenng, Xlanhul Bu Nature Vol388 21(1997) [Overview of the project] [Problems that the invention aims to solve]

[0008] As mentioned above, although various proposals have been made for resin compositions containing thermally expandable graphite, further improvement in fire spread prevention effectiveness is required. For example, when used as a component of window sashes, it is desirable to further improve the function of effectively preventing flames from penetrating the window sash to the outside by the adhesive force of the thermally expandable material remaining after a fire when the thermally expandable graphite rapidly expands. According to the inventors' studies, the expansion volume and adhesive force of a thermally expandable material tend to be inversely related. That is, there is a problem that the thermally expandable material tends to become brittle when the expansion volume is large. In this invention, the expansion volume and adhesive force of the properties of a thermally expandable material are collectively referred to as [expansion properties].

[0009] Therefore, the object of the present invention is to realize a resin composition in which both of the two conflicting properties of expansion volume and adhesive strength in a thermally expandable body are in good condition, a thermally expandable molded product or thermally expandable sheet formed from the resin composition, and a building component that has an excellent fire spread prevention effect using these thermally expandable molded products or thermally expandable sheets. More preferably, the object of the present invention is to realize the above object in a vinyl chloride resin-based resin composition such as vinyl chloride resin or chlorinated vinyl chloride resin that has excellent "resin properties" such as excellent flame retardancy and durability, easy compounding of additives such as thermally expandable graphite, ease of sheet manufacturing, and relatively low cost, and to provide a building component that has an even better fire spread prevention effect by utilizing a thermally expandable molded product or thermally expandable sheet formed from the above-mentioned vinyl chloride resin-based resin composition with excellent "resin properties". [Means for solving the problem]

[0010] The above-mentioned objective is achieved by the present invention as described below. That is, the present invention provides the following resin composition. [1] A resin composition characterized by containing a metal phosphate salt protonated monoamine storage material in which the metal is a divalent metal, a resin component, and thermally expandable graphite.

[0011] Preferred embodiments of the resin composition of the present invention described above are as follows. [2] The resin composition according to [1] above, wherein the metal phosphate protonated monoamine storage material is an ammonium metal phosphate salt. [3] The resin composition according to [2] above, wherein the ammonium phosphate metal salt is substantially represented by the structural formula (NH4)2M2P2O8 (where M is a divalent metal). [4] The resin composition according to [3] above, wherein M in the structural formula is one or more metals selected from the group consisting of divalent metals zinc, iron, copper, and nickel. [5] The resin composition according to [3] above, wherein M in the structural formula is one or more metals selected from the group consisting of divalent metals zinc, iron, and copper.

[0012] [6] The resin composition according to any one of [1] to [5] above, wherein the resin component is a vinyl chloride resin and / or a chlorinated vinyl chloride resin. [7] The resin composition according to any one of [1] to [6] above, wherein the thermally expandable graphite is contained in an amount of 10 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the resin component.

[0013] As another embodiment of the present invention, the following thermally expandable molded article is provided. [8] A thermally expandable molded article comprising the resin composition according to any one of [1] to [7] above.

[0014] As another embodiment of the present invention, the following thermally expandable sheet is provided. [9] A thermally expandable sheet comprising the resin composition according to any one of [1] to [7] above.

[0015] As another embodiment of the present invention, the following fitting is provided.

[10] A fitting comprising the thermally expandable molded article according to [8] above.

[0016] As another embodiment of the present invention, the following fitting is provided.

[11] A fitting comprising the thermally expandable sheet according to [9] above. Effects of the Invention

[0017] According to the present invention, it is possible to provide a resin composition in which two conflicting properties, expansion volume and adhesive strength, of the thermal expandable material remaining in the event of a fire are both in a good state, to provide a thermal expandable molded product or thermal expandable sheet formed from the resin composition, and further, to provide building components that have a superior fire spread prevention effect by utilizing these thermal expandable molded products or thermal expandable sheets. In addition, according to a preferred configuration of the present invention, in addition to the thermal expandable material remaining in the event of a fire having the above-mentioned excellent properties, it is possible to provide a vinyl chloride resin-based resin composition such as vinyl chloride resin or chlorinated vinyl chloride resin that has excellent "resin properties" such as excellent flame retardancy and durability, the ability to easily compound additives such as thermal expandable graphite, ease of sheet manufacturing, and relatively low cost, and to provide a thermal expandable molded product or thermal expandable sheet formed from a resin composition that also has excellent "resin properties" as described above, and by utilizing such thermal expandable molded products or thermal expandable sheets, it is possible to provide building components that have a superior fire spread prevention effect. [Brief explanation of the drawing]

[0018] [Figure 1] This shows the results of thermogravimetric differential thermal analysis (TG-DTA) on the fine-grained sample synthesized in Manufacturing Example 1. [Figure 2] For reference, here are the results of thermogravimetric differential thermal analysis (TG-DTA) of zinc ethylenediamine phosphate. [Modes for carrying out the invention]

[0019] The present invention will be described in detail below with reference to preferred embodiments. The resin composition of the present invention is characterized by containing a metal phosphate protonated monoamine storage medium in which the metal is a divalent metal, a resin component, and thermally expandable graphite. Preferred embodiments include the fact that the metal phosphate protonated monoamine storage medium is an ammonium metal phosphate salt, and that the ammonium metal phosphate salt is substantially represented by the structural formula (NH4)2M2P2O8 (where M is a divalent metal). More preferably, the metal of the ammonium metal phosphate salt, i.e., M in the above structural formula, is one or more selected from the group consisting of divalent metals consisting of zinc, iron, copper, and nickel, and more particularly, one or more selected from the group consisting of divalent metals consisting of zinc, iron, and copper. Hereinafter, the ammonium metal phosphate salt will be described as a representative example of the metal phosphate protonated monoamine storage medium that characterizes the present invention.

[0020] The metal phosphate protonated monoamine storage material that characterizes the present invention preferably has one of the compositions represented by the structural formula (NH4)2M2P2O8 (where M is a divalent metal) as described above. That is, it is preferable that M in the above formula is any of the divalent metals and the monoamine is ammonium. In particular, in the resin composition of the present invention, it is preferable to use an ammonium metal phosphate salt in which M in the above structural formula is one or more selected from the group consisting of zinc, iron, copper, and nickel, and in particular M is one or more selected from the group consisting of zinc, iron, and copper.

[0021] As described above, the resin composition of the present invention achieves its remarkable effects by containing a metal phosphate protonated monoamine adsorbent in which the metal is a divalent metal, such as an ammonium adsorbent of a metal phosphate salt represented by the above structural formula. As will be described later, according to the inventors' studies, the excellent effects of the present invention cannot be obtained with a resin composition that only contains the metal salt used in synthesizing the above adsorbent. In other words, the excellent effects obtained with the resin composition of the present invention can only be obtained by adding a metal phosphate protonated monoamine adsorbent in which the metal is a divalent metal, such as an ammonium adsorbent of a metal phosphate salt containing a divalent metal.

[0022] Generally, divalent metal salts of phosphate form diverse crystalline structures of the zeolite type (zeolite analogues) with microscopic pores. Specifically, by regularly linking tetrahedral structures, pores with diameters of several Å to tens of Å (Å = 0.1 nm), characteristic of zeolites, are regularly formed in one, two, and three dimensions, and molecules smaller than the pore size are absorbed within these pores. Pore size can be expressed by measuring the pore diameter, for example, in nanometers, or by the number of oxygen atoms contained in the pore rings, for example, as an 8-membered ring or a 10-membered ring. In cases where there are multiple membered rings, the largest membered ring is used as the representative.

[0023] Non-Patent Literature 1 describes the structure of tetramethylammonium zinc phosphate, which has a similar structure to the "protonated monoamine storage material of a metal phosphate salt in which the metal is a divalent metal" that constitutes the present invention, and states that the membered ring is a 4-membered ring. Non-Patent Literature 2 states that ethyleneamine zinc phosphate has an 8-membered ring. Non-Patent Literature 3 clearly shows the storage of protonated ethylenediamine molecules in zinc phosphate within the microscopic pores of a zeolite type. Non-Patent Literature 5 describes the microscopic pore structure of ethylenediamine cobalt phosphate within a zeolite type. Furthermore, Non-Patent Literature 6 contains a table listing zeolite-type structures with microscopic pores, consisting of various combinations of metals selected from the group consisting of aluminum, cobalt, gallium, cedium, and zinc, and various phosphates from various amines.

[0024] As described above, the microscopic pore structure of zeolite-type metal phosphate salts is diverse, but the technology of the present invention does not examine these structures. The technical feature of the present invention is that, as discovered by the inventors, the thermally expandable graphite in the resin composition expands rapidly during a fire, effectively solving the unique technical problems in the thermally expandable material that remains as residue, and providing a resin composition in which the thermally expandable material exhibits unprecedentedly superior expansion characteristics. Specifically, the inventors discovered a "metal phosphate protonated monoamine storage material in which the metal is a divalent metal" that characterizes the present invention, in which easily evaporable ammonia is stabilized by being adsorbed into the microscopic pore structure of zeolite-type metal phosphate salts. By applying a resin composition containing thermally expandable graphite formulated with such an ammonium metal phosphate salt to building materials, etc., the inventors found that the unique problem in thermally expandable material, which is the residue remaining after a fire, is that the thermally expandable material becomes brittle when the expansion volume is large, and thus arrived at the present invention. By using thermally expandable molded articles or thermally expandable sheets, etc., to which the resin composition of the present invention is applied, as components of building materials, it becomes possible to realize thermally expandable materials that exhibit unprecedentedly effective expansion characteristics in the event of a fire. This point will be discussed later.

[0025] Non-patent document 4 describes the synthesis of zinc ammonium phosphate from zinc chloride, ammonium hydrogen phosphate, urea, and hydrochloric acid, and performs thermal analysis of this compound using TG and DTA from room temperature to 900°C. Although this document does not specifically mention the microscopic pore structure of the zeolite type, it discloses that mass loss begins between 200 and 300°C, decreases rapidly after 300°C, and stabilizes after 500°C without significant further decrease. The mass loss rate from the initial stage to this stable region is 14.65%, which is said to match the assumed calculation value of 14.58% for decomposition in the following formula. 2NH4ZnPO4 ⇒ Zn2P2O7 + H2O + 2NH3

[0026] However, Non-Patent Document 4 describes the phase change of zinc phosphorus oxide produced during the thermal decomposition of zinc ammonium phosphate, and makes no mention whatsoever of the zeolite-type microporous structure, nor of the performance of the resin composition as a flame retardant. Naturally, the matters described in Non-Patent Document 4 are unrelated to the technical concept disclosed by the present invention as a new technology. In other words, Non-Patent Document 4 does not describe or suggest a resin composition containing a resin component and expandable graphite that results in a thermally expanded body formed during a fire, which is the subject of the present invention, having excellent expansion volume and viscous bonding strength ([expansion characteristics]).

[0027] A representative example of a metal phosphate protonated monoamine storage medium, in which the metal characterizing the present invention is a divalent metal, is an ammonium metal phosphate, which can be substantially represented by the following structural formula (A). (NH4)2M2P2O8(A) In structural formula (A), M represents any of the divalent metals. According to the inventors' studies, it is preferable that M in the formula is one or more selected from the group of divalent metals consisting of zinc, iron, copper, and nickel, and more preferably that M in the formula is one or more selected from the group of divalent metals consisting of zinc, iron, and copper.

[0028] As will be discussed later, flame retardants containing nitrogen and phosphorus are known to exhibit excellent flame retardancy. As described below, in studies of the expansion properties of resin compositions consisting of thermally expandable graphite and resin components in the prior art, the combined use of compounds containing nitrogen and phosphorus has been proposed in numerous cases. For example, Patent Document 1, mentioned above, discloses that by blending a compound having an amino group with a vinyl chloride resin-based resin composition containing thermally expandable graphite, the thermally expandable body exhibits good adhesive strength. Furthermore, Patent Document 1 states that the adhesive strength of the thermally expandable body can be further enhanced by using an amino group-containing compound and / or an ammonium-containing compound in combination. It also states that the contribution of ammonium polyphosphate to the improvement in adhesive strength of the thermally expandable body in the test is due to the ammonium in its structure. From this, it can be expected that using a compound containing ammonium will have the effect of enhancing the adhesive strength of the thermally expandable body, which is one of the issues addressed by the present invention.

[0029] However, our inventors' research revealed that ammonium, the cation of ammonia, is highly volatile and therefore could not be used in resin compositions. In response, we discovered that by adsorbing ammonium into a zeolite-type microporous structure and using this adsorbent as a constituent material of the resin composition, we could prevent the volatilization of ammonium and obtain a resin composition that exhibits excellent expansion characteristics in a thermally expandable material, which is a specific challenge of this invention, as described above. This led to the present invention.

[0030] Numerous basic amine compounds can be adsorbed into the microscopic pore structure of zeolite-type materials. However, our research indicates that the amount of basic amine compound used in this adsorption process must be far greater than the amount that can be adsorbed. On the other hand, the excess basic amine used in the adsorption process must ultimately be neutralized and washed with a large amount of water. The wastewater generated at this time has adverse effects on aquatic organisms. In contrast, ammonium chloride, a neutralized form of ammonium, is designated as a highly toxic substance, and it is said that ingesting large amounts can cause health problems. However, it is also approved for use as a food additive in bread and confectionery as a nutrient source for budding yeast. Given that ammonium chloride is widely used in bread, confectionery, and biscuits as one of the components of baking powder, it is qualitatively different from other organic amines, and it is expected that measures regarding wastewater treatment will be easier to implement.

[0031] On the other hand, as a conventional technique, phosphorus compounds are also used to improve the expandability of resin compositions containing thermally expandable graphite. In vinyl chloride resin systems, the addition of various inorganic and organic phosphorus compounds is also recommended. For example, Patent Document 2 proposes a fire-resistant resin composition in which the matrix resin is vinyl chloride resin, epoxy resin, etc., and which suppresses the spread of fire caused by ignition due to the generation of flammable gases due to the decomposition of lower phosphates (suppresses the spread of flames due to self-combustion) while maintaining fire resistance. Furthermore, Patent Document 4 states that by reducing the amount of inorganic filler in the fire-resistant resin composition and including phosphorus compounds such as phosphorus-based plasticizers, a fire-resistant resin composition that can obtain both excellent fire resistance and workability is provided. In contrast to the above-mentioned conventional techniques, the present invention solves the specific problem in the present invention that "thermal expandable materials tend to become brittle when the expansion volume is large" by newly applying a configuration in which phosphorus is incorporated into a compound with a special structure (ammonium storage of metal phosphate salt). Specifically, the present invention provides a resin composition in which a thermally expanding body that rapidly expands during a fire exhibits excellent [expansion characteristics] that prevent the spread of fire.

[0032] Patent Document 3 describes a technology that found that certain metal species exhibit a dehydrochlorination catalyst effect in the thermal decomposition of polyvinyl chloride resin, and that by using this dehydrochlorination catalyst in combination with a phosphorus compound, the thermally expanded body formed by foaming (expanding) with heat has excellent shape retention, being less prone to collapse and not easily blown away by flame pressure. Specifically, it states that in the low temperature range where there is almost no weight loss in the case of polyvinyl chloride resin without any additives, only when a specific substance is added does a significant decrease in the mass of the polyvinyl chloride resin occur, and dehydrochlorination (polyene formation) and carbonization are promoted. By utilizing this fact and configuring the system to effectively exhibit this effect, a thermally expandable polyvinyl chloride resin composition can be obtained that can effectively exhibit flame and smoke blocking functions in a low temperature range, and the expanded body after expansion has excellent shape retention and mechanical strength. In this invention, by finding a new configuration in which at least one of the divalent metal species is incorporated into a special structure for polyvinyl chloride resin, the present invention has achieved the goal of providing a polyvinyl chloride resin composition in which the thermally expanded body formed during a fire has excellent expansion characteristics.

[0033] Generally, flame retardants containing nitrogen and phosphorus are called intomessent flame retardants. When this type of flame retardant is included in a resin component, a carbonized film is formed due to the action of phosphorus, and the carbonized film becomes foamy due to the generation of gas by nitrogen, thereby suppressing the decomposition of the resin component. This makes it possible to raise the flame retardancy level of the resin component, for example, the UL standard grade. However, the expansion characteristics in a resin composition containing thermally expandable graphite relate to the evaluation of the thermally expanded material of the residue after the resin composition has completely burned, and therefore differ from the evaluation of delaying the combustion of the resin component, such as the UL standard mentioned above. In this invention, a special structure intomessent compound (flame retardant) containing at least one of two divalent metal species, ammonium (nitrogen component), and phosphorus was synthesized, and the effect on the expansion characteristics of the thermally expanded material was investigated, resulting in the realization of a vinyl chloride resin-based resin composition with unprecedentedly superior thermally expanded material expansion characteristics.

[0034] The inventors of the present invention, in the process of diligently studying to prepare a resin composition with superior expansion properties for thermal expanders, which solves the unique problem of the present invention that "thermal expanders tend to become brittle when the expansion volume is large," discovered the following. They synthesized a metal phosphate protonated monoamine storage material in which metal M, substantially represented by the structural formula "(NH4)2M2P2O8" described above, is a divalent metal, and investigated its application to resin compositions. In the above structural formula (A), M represents any divalent metal. In the investigation, they synthesized an ammonium metal phosphate salt in which M is one or more selected from the group of divalent metals consisting of zinc, iron, copper, and nickel, and diligently studied its blending with various resins, particularly vinyl chloride resin or chlorinated vinyl chloride resin which have excellent resin properties, and resin compositions containing thermally expandable graphite. As a result, they discovered a new configuration for a resin composition in which the thermal expander that is rapidly formed in the event of a fire exhibits good expansion properties in both expansion volume and adhesive strength, two conflicting properties that are the target of the present invention.

[0035] As a prior art application of the type of material discussed above to a resin composition, there is the aforementioned Patent Document 5. The material described in Patent Document 5 is PO4 3- HPO4 2- and H2PO 4- One or more ions selected from the group consisting of and Zn 2+ This is a three-dimensional open skeleton composed of a combination of elements, in which a protonated cation of an amine is adsorbed. Furthermore, in the invention described in Patent Document 5, it is stated that the amine adsorbed into the three-dimensional open skeleton is preferably one that has two or more amino groups in one molecule, from the viewpoint of thermal stability. Patent Document 5 basically describes a compound in which a diamine is adsorbed into a three-dimensional open skeleton structure of zinc phosphate. Examples of diamines are given as ethylenediamine, propylenediamine, 1,4-diaminobutane, and 1,6-diaminohexane. In addition, Patent Document 5 also provides examples of amines with a larger number of functional groups than diamines, such as diethylenetriamine, triethylenetetramine, and hexamethylenetetramine, as amines adsorbed into the three-dimensional open skeleton.

[0036] However, this prior art concerns flame-retardant resin compositions and aims to improve the flame retardancy level (UL standard) of the resin, so its purpose, structure, and effects are completely different from those of the present invention. In other words, the present invention aims to solve the specific problem in resin compositions containing thermally expandable graphite, where, in the event of a fire, the thermally expanded material, which is the residue, tends to become brittle if the expansion volume is large. The present invention has found a structure and effects to improve both the expansion volume and the adhesive strength, which are conflicting properties of the thermally expanded material, but Patent Document 5 neither describes nor suggests these points. Due to these differences, the present invention also considers metal species other than zinc, which are not addressed in the technology of Patent Document 5, and has found a structure that can obtain the unique effects of the present invention.

[0037] The microscopic pore structure of the zeolite-type metal phosphate salt is an anion gauge, and the protonated amine cation is absorbed until it is electrically neutralized. However, amine species with two or more amino groups in one molecule, as listed in Patent Document 5 above, are extremely toxic and require strict handling. Once absorbed, they are electrically attracted to each other, so leakage from the zeolite-type microscopic pore structure is said to be minimal, but it cannot be said to be completely absent. In particular, in the absorption process, excess amine used beyond neutralization is removed by washing with water, but these amines are considered harmful to the aquatic environment, and there are problems with the easy treatment of the wastewater. On the other hand, while cationic ammonia is also harmful to the aquatic environment, in the case of ammonium, environmental protection can be addressed by simple methods such as converting it to ammonium chloride or ammonium sulfate in the washing process. For the reasons stated above, the absorbent used in the resin composition of the present invention is a metal phosphate salt protonated monoamine absorbent in which the metal is a divalent metal, and it is preferable that the monoamine is ammonium. This invention enables the preparation of a resin composition that solves the problem specific to this invention—improving the "expansion characteristics" of a thermally expandable material—by configuring it in this way, and at the same time, enables environmental protection, which is an important issue in the manufacturing process.

[0038] Next, we will describe the components other than the metal phosphate protonated monoamine storage bodies, represented by ammonium metal phosphate salts, which characterize the resin composition of the present invention. The thermally expandable graphite constituting the resin composition of the present invention is conventionally known graphite that expands when heated. This thermally expandable graphite is produced by immersing pulverized natural graphite, pyrolysis graphite, cached graphite, etc., in a solution of inorganic acid, organic acid, and strong oxidizing agent, and intercalating the acid into the graphite layer of the above-mentioned material. In the resin composition of the present invention, there are no particular restrictions on the particle size range, but generally, the degree of expansion of graphite is small if it is less than 200 mesh, and dispersion becomes difficult during the manufacture of the resin composition if it exceeds 600 mesh, so an appropriate mesh range should be selected according to the application. The relationship between the particle size (mesh) and degree of expansion of thermally expandable graphite is described in detail in the prior art patent document 7 mentioned above.

[0039] The resin components constituting the resin composition of the present invention include thermoplastic resins, thermosetting resins, elastomers, rubbers, and combinations thereof. Examples of thermoplastic resins include various olefin resins, various polyester resins, polystyrene resins, acrylic resins, polycarbonate resins, polyamide resins, vinyl chloride resins, polyurethane resins, and the like. There are no other particularly limited resins. Examples of thermosetting resins include polyurethane resins, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, and polyimide resins. Examples of elastomers include olefin elastomers, styrene elastomers, ester elastomers, amide elastomers, and vinyl chloride elastomers. Examples of rubbers include natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylic rubber, epichlorohydrin rubber, fluororubber, and urethane rubber.

[0040] Among the various resin components listed above, vinyl chloride resins, i.e., vinyl chloride resin and / or chlorinated vinyl chloride resin, are suitable for the present invention due to their excellent resin properties. As mentioned above, vinyl chloride resins have excellent resin properties, including flame retardancy, durability, the ability to easily compound additives such as thermally expandable graphite, ease of sheet manufacturing, and relatively low cost. These properties are key factors in selecting a suitable resin component. There are no particular restrictions on the molecular weight of the vinyl chloride resin used in the resin composition of the present invention, but a molecular weight of around 1000 to 5000 is preferable for ease of sheet manufacturing. The present invention has been described using vinyl chloride resin as a representative example of a resin component and illustrating a vinyl chloride resin-based resin composition, but the present invention is not limited thereto.

[0041] In the case of the resin composition of the present invention using a vinyl chloride resin as the resin component, the use of plasticizers is important to adjust the required properties of the sheet, particularly hardness. There are no limitations on the type of plasticizer used, but specifically, examples include phthalate ester plasticizers such as DOP, DBP, DHP, and DIDP; fatty acid ester plasticizers such as DOA, DIBA, and DBA; epoxidized ester plasticizers; trimellitic acid esters such as TOTM and TINTM; adipic acid polyester-based polyester plasticizers; and phosphate ester plasticizers such as TCP. The amount of plasticizer added can be appropriately determined based on the amount required for manufacturing the sheet and the desired hardness. When forming sheets by extrusion molding using the resin composition of the present invention, it is preferable to add about 5 to 35% plasticizer, and when manufacturing sheets by sol coating, it is preferable to add about 40 to 75% plasticizer. However, this is not limited to these.

[0042] As described earlier regarding the prior art, phosphorus and nitrogen have flame-retardant effects, and this is also followed in the resin composition of the present invention. Furthermore, Table 2 of Patent Document 3, described earlier, describes the catalytic effect of various metals and metal-containing compounds on polyvinyl chloride resin in terms of heat loss. In particular, zinc species show a special effect, and it is described that they exhibit excellent expansion properties in the presence of phosphorus.

[0043] In this invention, instead of individually evaluating phosphorus, basic nitrogen (ammonium), and specific divalent metal species, we synthesized structures adsorbed within microscopic pores, similar to intomessent flame retardants, and investigated their effect on the expansion properties of thermal expandable materials. As a result, all divalent metal species showed good results, but among them, one or more metals selected from the group consisting of zinc, iron, copper, and nickel, and in particular, one or more metals selected from the group consisting of zinc, iron, and copper, showed excellent effects. Furthermore, in this invention, the ammonium phosphate metal salt used was synthesized and used by referring to the synthesis method of amine-containing zinc phosphate described in Patent Document 5 described above.

[0044] The structure of the amine-containing zinc phosphate disclosed in Patent Document 5, mentioned above, is such that a protonated amine cation is adsorbed within a three-dimensional open skeleton of an anion composed of a phosphate ion and a metal ion. The amount of amine adsorbed within the three-dimensional skeleton is said to be limited to the amount that maintains electrical neutrality. Therefore, if the blending ratio required for adsorption is maintained, an adsorbent with a quantitative ratio can be obtained. However, Patent Document 6, mentioned above, states that when diethylenetriamine is used as the amine, the ratio of adsorbed amine changes when the blending conditions are changed. Furthermore, as will be described later, the mass loss due to amine desorption during heating changes with temperature. Based on these and other factors, we believe that the ammonium metal phosphate salt, which is representative of the metal phosphate protonated monoamine adsorbent that characterizes the resin composition of the present invention, can be substantially identified by the structural formula (A) described above.

[0045] As mentioned above, the ammonium metal phosphate salt, which is representative of the protonated monoamine storage material that characterizes the resin composition of the present invention, can be represented by the structural formula of the following formula (A). (NH4)2M2P2O8(A) In formula (A), M represents any of the divalent metals.

[0046] While the composition of the adsorbent characteristic of the present invention cannot be completely limited, the numerical value of the mass loss rate closely matches the calculated value from formula (A) above, so it was considered that it could be substantially described by structural formula (A). That is, the ammonium metal phosphate salt, which is representative of the metal phosphate protonated monoamine adsorbent characteristic of the resin composition of the present invention, cannot be specified as either a compound or a mixture. Therefore, in the present invention, various analyses were performed on the synthetic product produced as described later, and the results were expressed by structural formula (A). Furthermore, Patent Document 5 states that the flame retardant effect of ethylenediamine zinc phosphate is better when used in combination with a triazine derivative.

[0047] The ammonium metal phosphate salts, which are representative of the metal phosphate protonated monoamine storage bodies that characterize the resin composition of the present invention, were synthesized by referring to the synthesis method described in Patent Document 5 mentioned above, taking into account the dissolution conditions of the raw materials of various metals. [Examples]

[0048] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" refer to mass unless otherwise specified.

[0049] (Summary of the resin compositions of the examples and comparative examples) First, EM-1 to EM-4 were synthesized as ammonium metal phosphate salts characterizing the present invention using the method described later. Next, each of the obtained synthetic products was added to a mixture of polyvinyl chloride resin, thermally expandable graphite, and a plasticizer (DOP) and kneaded to prepare the resin compounds of the examples. For comparison, EA-1 to EA-3, corresponding to the above synthetic products, were used as metal phosphate salts that did not absorb ammonium, and were compounded in the same manner as in the examples to prepare the resin compounds of Comparative Examples 1 to 3. Furthermore, magnesium phosphate and calcium carbonate, which are common inorganic flame retardants, were used as EA-4 and EA-5, respectively, and were added in the same amounts as in the examples to prepare the resin compounds of Comparative Examples 4 and 5.

[0050] All raw materials used in the synthesis of ammonium metal phosphate salts were reagent products manufactured by Wako Pure Chemical Industries, Ltd., used as is. The metal phosphate salts used in the comparative examples were also reagent products manufactured by Wako Pure Chemical Industries, Ltd., used as is. For the polyvinyl chloride resin, we used Ryuron Paste 772A (product name) manufactured by Tosoh Corporation. For the thermally expandable graphite, we used SYZR502 (product name) manufactured by Sanyo Trading Co., Ltd. For the plasticizer, we used Sanso-Sizer DOP (product name) manufactured by Shin-Nippon Rika Co., Ltd. Table 1 summarizes the formulations of the resin compounds (resin compositions).

[0051] TIFF0007912357000001.tif50170

[0052] The ammonium phosphate metal salts EM-1 to EM-4 used in Examples 1 to 4 were prepared as follows.

[0053] [Manufacturing Example 1] (Production of zinc ammonium phosphate): EM-1 A solution was prepared by mixing 570 parts zinc sulfate with 509 parts purified water. To this solution, 313 parts of 75% phosphoric acid were added dropwise over 1 hour to prepare a solution containing zinc sulfate and phosphoric acid. Next, a mixture of 243 parts purified water and 444 parts of 28% ammonia solution was added dropwise to the zinc sulfate and phosphoric acid solution over approximately 1 hour under ice cooling. A white precipitate was formed during the dropwise addition, so vigorous stirring was necessary to prevent aggregation. After the addition was complete, stirring was stopped and the mixture was left at room temperature for 24 hours. Next, the supernatant was removed by decantation. The residue was filtered and washed four times with 5 L of purified water. The filtered residue (synthetic product) was dried at 90°C for 48 hours, then ground in a mill to obtain fine granules. The yield of the finely granulated sample was 99%.

[0054] The structural formula of the sample EM-1 (ammonium-adsorbed zinc phosphate) obtained by the above method was assumed to be (NH4)2Zn2P2O8. Various analyses were performed on the fine-grained sample obtained by the above production method, and the measured values ​​were compared with the calculated values.

[0055] The elemental composition ratios were measured using a Keyence EA-300 laser elemental analyzer (product name). The calculated zinc / phosphorus mass ratio was 68 / 32, while the measured value was 65 / 35, which was in good agreement with the structural formula described above. The nitrogen content was measured using the inert gas fusion-thermoelectric method. As a result, the measured value was 7.5%, compared to the calculated value of 7.9%, which was in good agreement with the structural formula described above.

[0056] Furthermore, the fine-grained samples synthesized as described above were analyzed by X-ray diffraction. Measurements were taken using characteristic X-rays: CuKa / 1.541862 Å, 45 KV, 200 mmA. Diffraction charts were obtained and are shown in Table 2. For zinc ammonium phosphate, since there was no data available in the 2θ table (which summarizes the 2θ (2-theta) values ​​representing the X-ray scattering angle), Table 2 lists the relatively high peaks for the fine-grained samples synthesized in Production Example 1, excluding the 2θ values ​​specific to various known zinc phosphates from the obtained measurements. For reference, Table 2 also includes the peak values ​​for ethylenediamine zinc phosphate, which were measured separately.

[0057] TIFF0007912357000002.tif66170

[0058] Furthermore, the fine-grained sample synthesized in Production Example 1 was subjected to TG-DTA (thermogravimetric differential thermal analysis) in a nitrogen stream, in accordance with Non-Patent Document 4 described earlier, from room temperature to 600°C. The results were in good agreement with the information described in Non-Patent Document 4. Figure 1 shows the TG-DTA results for the fine-grained sample synthesized above. As shown in Figure 1, the mass loss at 600°C was 14.2%, which is close to the calculated value of 14.6% assuming ammonium volatilization based on the aforementioned structural formula.

[0059] Furthermore, since the TG-DTA measurement results described in Non-Patent Literature 4 showed almost no mass loss from 600°C up to 1000°C, a simple method for measuring ammonia desorption was performed by heating to 600°C for 15 minutes in a standard electric furnace. As a result, a mass loss of 14.6% was confirmed.

[0060] Based on the results of the various analyses described above, it was confirmed that the method of Production Example 1 yields zinc ammonium phosphate, a representative example of a protonated monoamine storage material of a metal phosphate salt, where the metal specified in the present invention is a divalent metal. The method of Production Example 1 was basically applied to the production of various metal salts below. However, for some metal salts, a raw material other than a sulfate was used, and the amount of water used as the solvent was adjusted considering solubility. The zinc ammonium phosphate obtained by the method of Production Example 1 was white.

[0061] The TG-DTA curve for the fine-grained sample synthesized by the method of Production Example 1, as shown in Figure 1, did not show a smooth decrease in mass from room temperature to 600°C, but rather exhibited several shoulders. The inventors believe that this result may indicate that there is a unique element in the detachment of ammonium trapped in the zeolite-type micropore structure upon heating, and therefore there may be factors that affect the expansion properties of thermally expandable graphite. For reference, the TG-DTA curve for ethylenediamine zinc phosphate is shown in Figure 2. The TG-DTA curve for ethylenediamine zinc phosphate, as shown in Figure 2, showed a typical smooth decrease in mass.

[0062] [Manufacturing Example 2] (Production of Ammonium Copper Phosphate): EM-2 In this production example, ammonium copper phosphate salt EM-2 was synthesized according to the method of Production Example 1, which synthesized ammonium zinc phosphate. Using 70 parts anhydrous copper sulfate, 112 parts purified water, and 70 parts 75% phosphoric acid, a solution containing copper sulfate and phosphoric acid was prepared according to Production Example 1. Next, a mixture of 108 parts of pre-prepared purified water and 91 parts of 28% ammonia solution was added dropwise according to Production Example 1. The resulting residue was then washed with purified water in the same manner as in Production Example 1, dried, and then ground into fine granules using a mill.

[0063] The yield of the finely granulated sample (copper phosphate with ammonium adsorbed) EM-2 obtained above was 92%, assuming its structural formula to be (NH4)2Cu2P2O8. The obtained finely granulated sample was blue in color. The calculated mass ratio of copper / phosphorus was 65 / 35, while the measured value was 63 / 37, which was an approximate value.

[0064] [Manufacturing Example 3] (Production of ammonium iron phosphate): EM-3 In this production example, ammonium iron phosphate EM-3 was synthesized according to the method of Production Example 1, which synthesized ammonium zinc phosphate. Using 184 parts of ferric sulfate heptahydrate, 342 parts of purified water, and 104 parts of 75% phosphoric acid, a solution containing ferric sulfate and phosphoric acid was prepared according to Production Example 1. A mixture of 162 parts of purified water and 136 parts of 28% ammonia solution was added dropwise according to Production Example 1. The resulting residue was then washed with purified water in the same manner as in Production Example 1, dried, and then ground into fine granules using a mill.

[0065] The yield of the finely granulated sample (iron phosphate salt with ammonium adsorbed) EM-3, whose structural formula is assumed to be (NH4)2Fe2P2O8, was 98%. The obtained finely granulated sample was light black in color. The calculated mass ratio of iron / phosphorus was 69 / 31, while the measured value was 67 / 33, which was an approximate value.

[0066] [Manufacturing Example 4] (Production of ammonium nickel phosphate): EM-4 In this production example, nickel ammonium phosphate salt EM-4 was synthesized according to the method of Production Example 1, which synthesized zinc ammonium phosphate. A solution containing nickel acetate and phosphoric acid was prepared according to Production Example 1 using 133 parts nickel acetate tetrahydrate, 406 parts purified water, and 118 parts 75% phosphoric acid. A mixture of 131 parts purified water and 110 parts 28% aqueous ammonia was added dropwise according to Production Example 1. The resulting residue was washed with purified water in the same manner as in Production Example 1, dried, and then ground into fine granules using a mill.

[0067] The yield of the finely granulated sample obtained above (nickel phosphate salt with ammonium adsorbed) EM-4 was 96%, with the structural formula being (NH4)2Ni2P2O8. The obtained finely granulated sample was yellowish-brown in color. The calculated nickel / phosphorus mass ratio was 68 / 32, while the measured value was 72 / 28, which was a slightly different value compared to production examples 1-3.

[0068] [EA-1 to EA-5 used in the comparative example] In Comparative Examples 1 to 5, instead of EM-1 to EM-4, the ammonium metal phosphate salts that characterize the present invention and were synthesized in Production Examples 1 to 4 as described above and used in the Examples, the following EA-1 to EA-5 were used, respectively. Unlike EM-1 to EM-4, EA-1 to EA-4 used in Comparative Examples 1 to 4 are all metal phosphate salts that do not absorb ammonium. Furthermore, EA-5 used in Comparative Example 5 is calcium carbonate. In order to compare with EM-1 to EM-4 used in the Examples, EA-1 to EA-5 used in the Comparative Examples were used in the same amount as EM without considering the amount of hydrate.

[0069] EA-1: Zinc phosphate tetrahydrate EA-2: Copper Phosphate EA-3: Iron phosphate n-hydrate EA-4: Magnesium triphosphate octahydrate EA-5: Calcium carbonate

[0070] (Preparation of resin compositions of the examples and comparative examples) Resin compounds (resin compositions) for Examples 1-3 and Comparative Examples 1-5 were prepared using the formulations described in Table 1. For Examples 1-3, the ammonium phosphate metal salts EM-1-EM-3 that constitute the resin compositions were the finely ground samples obtained in the previously described production examples 1-3. For Comparative Examples 1-3, EA-1-EA-3 are all phosphate metal salts that do not contain ammonium; EA-4 is magnesium phosphate, a common inorganic flame retardant, and EA-5 is calcium carbonate, a common inorganic flame retardant. EM-1-EM-3 used in the examples and EA-1-EA-3 used in the comparative examples are all phosphate salts, and their contained metals correspond to zinc, copper, and iron, respectively.

[0071] As mentioned above, similarly, the resin compounds of Examples 1 to 3 were prepared by adding and kneading EM-1 to EM-3, which were synthesized earlier, to the polyvinyl chloride resin, thermally expandable graphite, and plasticizer (DOP) formulations shown in Table 1. In addition, the resin compounds of Comparative Examples 1 to 3 were prepared by adding and kneading EA-1 to EA-3, which are metal phosphate salts that do not absorb ammonium as described earlier, to the polyvinyl chloride resin, thermally expandable graphite, and plasticizer (DOP) formulations shown in Table 1. Furthermore, Comparative Example 4 was prepared by adding magnesium phosphate, a common inorganic flame retardant, to the mixture of polyvinyl chloride resin, thermally expandable graphite, and plasticizer (DOP) as shown in Table 1 and kneading it together. Similarly, Comparative Example 5 was prepared by adding calcium carbonate, a common inorganic flame retardant, to the mixture of polyvinyl chloride resin, thermally expandable graphite, and plasticizer (DOP) and kneading it together.

[0072] (Preparation of sample sheets for examples and comparative examples) All of the resin compounds prepared above were in sol-liquid form in both the examples and comparative examples. Using these sol-liquid resin compositions (resin compounds), heat-expandable sheets (sample sheets) were prepared as follows. Each of the sol-liquid resin compositions obtained above was poured into an aluminum mold that had been pre-coated with a silicone release agent. The molds were heated at 90°C for 20 minutes, then at 160°C for 20 minutes to release the mixture, and sample sheets for the examples and comparative examples were prepared, each measuring 45 mm in length, 20 mm in width, and 2 mm ± 0.1 mm in thickness.

[0073] (evaluation) The expansion characteristics of the thermal expander were evaluated using the following method with each sample sheet prepared in the above-mentioned examples. An open-top aluminum container with a base of 20 mm x 45 mm and a height of 50 mm was prepared. Using each sample sheet prepared in the above-mentioned examples, the sample sheet cut to the same dimensions was attached to the base of the prepared container, the base of the container was placed perpendicular to the aluminum plate, and the container was inserted into an electric furnace at 500°C. After insertion, the temperature inside the electric furnace briefly drops below 500°C, but the sample sheet immediately ignites, and the temperature begins to rise, exceeding 500°C. As combustion weakens, the temperature rise slows down, and eventually reverses and begins to decline. When the temperature inside the electric furnace reaches 500°C, combustion ends, and the formation of the thermal expander residue is completed. The thermal expander was immediately removed from the container and used as a test sample.

[0074] The height of the thermal expansion body sample obtained as described above was measured, and the value obtained by dividing the measured value by the measured thickness of the original sheet was taken as the expansion ratio (foaming ratio) and used as the evaluation value for the "expansion volume" of the expansion characteristics. In addition, a 100 mm diameter disc was placed on top of this thermal expansion body, and the thermal expansion body was compressed to 15 mm from the floor using a compression measuring instrument. The maximum resistance force obtained in this process was taken as the "cohesive force" and used as the evaluation value for the expansion characteristics. Table 3 summarizes the foaming ratio, which is the evaluation value for the "expansion volume" of the thermal expansion body, and the "cohesive force" of the thermal expansion body measured for each sample sheet used in the evaluation test as described above. The values ​​in parentheses for the cohesive force and foaming ratio in Examples 1 to 3 indicate the percentage improvement in the effect of the cohesive force or foaming ratio, compared to Comparative Examples 1 to 3, which used metal phosphate salts that did not absorb the same ammonium as the corresponding metal, as the baseline.

[0075] TIFF0007912357000003.tif79170

[0076] As shown in Examples 1-3 of Table 3, by applying the resin composition using the ammonium metal phosphate salt that characterizes the present invention, it was confirmed that the thermally expanded material remaining after a fire exhibits superior expansion characteristics, showing 1.4 to 3.3 times higher adhesive strength and a foaming ratio of the same or greater, compared to the resin compositions using metal phosphate salts of Comparative Examples 1-3, where the contained metal does not contain the corresponding ammonium. Furthermore, in comparison with Comparative Examples 4 and 5, which used general inorganic flame retardants, it was confirmed that the sample sheets made from the resin compositions using metal phosphate salts of Examples 1-3 formed a thermally expanded material with adhesive strength nearly 2 to 3 times higher, and the foaming ratio also improved to about 1.1 to 1.25 times.

Claims

1. A resin composition characterized by containing an ammonium metal phosphate, which is a metal phosphate protonated monoamine storage material in which the metal is a divalent metal, a resin component, and thermally expandable graphite.

2. The ammonium phosphate metal salt has the structural formula (NH ４ ) ２ M ２ P ２ O ８ The resin composition according to claim 1, represented by (where M in the structural formula is a divalent metal).

3. The resin composition according to claim 2, wherein M in the structural formula is one or more metals selected from the group consisting of divalent metals zinc, iron, copper, and nickel.

4. The resin composition according to claim 2, wherein M in the structural formula is one or more metals selected from the group consisting of divalent metals zinc, iron, and copper.

5. The resin composition according to claim 1 or 2, wherein the resin component is a vinyl chloride resin and / or a chlorinated vinyl chloride resin.

6. The resin composition according to claim 1 or 2, wherein the thermally expandable graphite is contained in an amount of 10 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the resin component.

7. A heat-expandable molded article characterized by comprising the resin composition described in claim 1 or 2.

8. A heat-expandable sheet characterized by comprising the resin composition described in claim 1 or 2.

9. A joinery piece characterized by comprising the heat-expandable molded body described in claim 7.

10. A joinery piece characterized by comprising the thermally expandable sheet described in claim 8.

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