Flame-retardant resin composition and flame-retardant resin housing

Abstract

To provide a flame-retardant resin composition capable of producing a molded product having reduced environmental load and excellent flame retardancy, color tone and impact strength, and to provide a flame-retardant resin housing produced using the flame-retardant resin composition.SOLUTION: There is provided a flame-retardant resin composition which comprises a thermoplastic resin and a flame retardant, wherein the flame retardant includes a mixture of one or more acidic polysaccharides selected from a polysaccharide having an acidic functional group, a derivative of the polysaccharide having an acid functional group modified by leaving at least a portion of the acid functional group and a salt thereof and a non-reactive organic silicon compound or a reaction product of the acidic polysaccharide, a reactive organic silicon compound having reactivity with the acidic polysaccharide and the acidic polysaccharide.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a flame-retardant resin composition and a flame-retardant resin housing. More specifically, the present invention relates to a flame-retardant resin composition that reduces environmental impact and enables the production of molded articles with excellent flame retardancy, colorability, and impact strength, and to a flame-retardant resin housing manufactured using the flame-retardant resin composition. [Background technology]

[0002] In recent years, with the growing demand for reducing environmental impact, biomass resins, which replace petroleum raw materials with biodegradable biomass raw materials, have attracted attention. The use of biomass resins is expected to reduce energy consumption during manufacturing and carbon dioxide emissions during final incineration compared to petroleum-based resins (resins synthesized from petroleum).

[0003] Generally, resin products are manufactured by adding various additives to resin according to their intended purpose. The use of biomass raw materials with low environmental impact is also expected for such additives. For example, polysaccharides are known to be incorporated into resin compositions as flame retardants to reduce environmental impact (see, for example, Patent Document 1). Polysaccharides are compounds with a cyclic structure containing a large amount of hydroxyl groups as their basic framework. During combustion, they generate water vapor as a result of dehydration condensation accompanied by heating, resulting in flame retardancy through cooling due to a large amount of endothermic heat, dilution of combustion gases, and blocking of oxygen. Furthermore, it is expected that the carbonization of dehydrated polysaccharides forms a heat-insulating film (char (carbonized layer)), thereby exhibiting flame retardancy.

[0004] However, resin compositions containing polysaccharides are prone to discoloration due to heating during the molding process to obtain molded products, and this thermal discoloration impairs the colorability of the molded products. Additionally, foaming reduces impact strength, which poses a problem. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2006-77215 [Overview of the project] [Problems that the invention aims to solve]

[0006] This invention has been made in view of the above-mentioned problems and circumstances, and its objective is to provide a flame-retardant resin composition that reduces environmental impact and enables the production of molded articles with excellent flame retardancy, colorability, and impact strength, as well as a flame-retardant resin housing manufactured using the flame-retardant resin composition. [Means for solving the problem]

[0007] In order to solve the above problems, the inventors of the present invention, in the process of investigating the causes of the above problems, discovered that by incorporating a mixture of an acidic polysaccharide, consisting of one or more selected from polysaccharides having acidic functional groups, their derivatives, and salts thereof, and a non-reactive organosilicon compound, or a reaction product of an acidic polysaccharide and a reactive organosilicon compound having a reactive nature, into a resin composition, a flame-retardant resin composition can be obtained that reduces environmental impact and allows for the production of molded articles with excellent flame retardancy, colorability, and impact strength, leading to the present invention. In other words, the above-mentioned problems according to the present invention are solved by the following means.

[0008] 1. A flame-retardant resin composition containing a thermoplastic resin and a flame retardant, The aforementioned flame retardant is a mixture of an acidic polysaccharide and a non-reactive organosilicon compound, consisting of one or more selected from polysaccharides having acidic functional groups, derivatives of polysaccharides having acidic functional groups modified while retaining at least a portion of the acidic functional groups, and salts thereof. ,before Reaction product of a reactive organosilicon compound that is reactive with the acidic polysaccharide and the acidic polysaccharide. or both of the mixture and the reactants Contains death, The aforementioned acidic polysaccharide contains calcium alginate, The non-reactive organosilicon compound does not have a functional group that is reactive with the acidic polysaccharide. The ratio of the non-reactive organosilicon compound to the acidic polysaccharide in the mixture is within the range of 2 to 30% by mass. The ratio of the reactive organosilicon compound to the acidic polysaccharide in the reaction product is within the range of 2 to 30% by mass. The mixture and the reaction product are acidic polysaccharide-based flame retardants. The content of the aforementioned acidic polysaccharide-based flame retardant is within the range of 5 to 40% by mass relative to the total amount of the flame retardant resin composition. A flame-retardant resin composition characterized by [having the following properties].

[0009] 2. The flame-retardant resin composition according to paragraph 1, characterized in that the flame-retardant resin composition contains the reactant, and the reactive organosilicon compound contains a reactive silicone oil or a silane coupling agent.

[0011] 3 The first item is characterized in that the ratio of the unreactive organosilicon compound to the acidic polysaccharide in the mixture and the ratio of the reactive organosilicon compound to the acidic polysaccharide in the reactant are each within the range of 2 to 30% by mass. or The In item 2 The flame-retardant resin composition described.

[0013] 4 Furthermore, the flame retardant is contained in an amount of 1 to 20% by mass relative to the total amount of the flame retardant resin composition, as described in paragraphs 1 to 1. 3 A flame-retardant resin composition as described in any one of the items up to item [number].

[0014] 5 A flame-retardant resin housing made using a flame-retardant resin composition, The flame-retardant resin composition is as described in paragraphs 1 to 1. 4 A flame-retardant resin housing characterized by being a flame-retardant resin composition as described in any one of the items up to item [number]. [Effects of the Invention]

[0015] The above-described means of the present invention make it possible to provide a flame-retardant resin composition that reduces environmental impact and enables the production of molded articles with excellent flame retardancy, colorability, and impact strength, as well as a flame-retardant resin housing manufactured using the flame-retardant resin composition. The mechanism of action or mechanism of the effects of the present invention is presumed to be as follows.

[0016] As described above, hydrocarbons rich in oxygen atoms within their molecules, such as polysaccharides, undergo a dehydration reaction during combustion, losing oxygen and hydrogen to form carbon and creating a carbonized layer. This carbonized layer is difficult to burn, acts as an insulating layer to suppress the decomposition of new resins, and inhibits the diffusion of resin decomposition products, i.e., flammable gases, generated within the carbonized layer to the outside. For this reason, it is known that flame retardancy is achieved, stopping the combustion reaction.

[0017] The inventors have found that using polysaccharides that have acidic functional groups in their molecules promotes the above-mentioned dehydration reaction. While cellulose, a representative polysaccharide, does not have acidic functional groups, many other polysaccharides do have acidic functional groups such as carboxyl groups, and these acidic functional groups assist in the formation of the carbonized layer. In these acidic polysaccharides, the acidic functional groups are directly bonded to the main chain, resulting in a short distance between the acidic functional groups and the main chain, and thus a strong carbonization promoting effect.

[0018] However, its susceptibility to carbonization makes it prone to discoloration, such as turning brown, due to heat. The heat of melting during mixing and molding, frictional heat with the walls, and the increase in compression temperature due to pressurization can easily cause browning, especially on the surface. As a result, it becomes difficult to achieve any color other than dark colors like black in the molded product, resulting in a narrow range of tonality, or in other words, insufficient tonality. In addition, acidic polysaccharides are prone to decomposition and foaming due to the heat during mixing and molding. This results in porous parts in the molded product, leading to a decrease in impact strength.

[0019] To address the above issues, the inventors have discovered that colorability and impact strength can be improved by using acidic polysaccharides in combination with organosilicon compounds, specifically by combining acidic polysaccharides with non-reactive organosilicon compounds, or by using reaction products of acidic polysaccharides with reactive organosilicon compounds that have reactivity with acidic polysaccharides.

[0020] In flame-retardant resin compositions containing acidic polysaccharides, thermal discoloration and foaming during molding occur throughout the pellets and molded products, but are particularly pronounced near the surface. This is thought to be because, during molding, the acidic polysaccharides, which are rich in functional groups such as hydroxyl groups and acidic functional groups, experience strong friction with the metal surface in the narrow passages of the kneader and molding machine, resulting in discoloration due to frictional heat and foaming due to decomposition gases. Therefore, it is thought that using acidic polysaccharides in combination with organosilicon compounds reduces the coefficient of friction on the surface of the acidic polysaccharides, thereby suppressing discoloration and foaming. [Modes for carrying out the invention]

[0021] The flame-retardant resin composition of the present invention is a flame-retardant resin composition containing a thermoplastic resin and a flame retardant, characterized in that the flame retardant contains a mixture of an acidic polysaccharide and a non-reactive organosilicon compound, which consists of one or more selected from a polysaccharide having an acidic functional group, a derivative of the acidic functional group having an acidic functional group modified while retaining at least a portion of the acidic functional group, and salts thereof, or a reaction product of a reactive organosilicon compound that is reactive with the acidic polysaccharide and the acidic polysaccharide. This feature is a technical feature common to each of the embodiments described below.

[0022] In embodiments of the present invention, from the viewpoint of achieving the effects of the present invention, it is preferable that the flame-retardant resin composition contains the reactant, and the reactive organosilicon compound contains a reactive silicone oil or a silane coupling agent. If the reactant is present, the organosilicon compound will be located in close proximity to the acidic polysaccharide, which makes it easier to reduce friction between the acidic polysaccharide and the molding apparatus, etc.

[0023] In embodiments of the present invention, from the viewpoint of achieving the effects of the present invention, it is preferable that the acidic polysaccharide contains calcium alginate. The calcium salt of alginate readily forms intermolecular crosslinking structures and has high heat resistance. Therefore, by using it, discoloration and decomposition during molding can be effectively suppressed.

[0024] In embodiments of the present invention, from the viewpoint of achieving the effects of the present invention, it is preferable that the ratio of the non-reactive organosilicon compound to the acidic polysaccharide in the mixture and the ratio of the reactive organosilicon compound to the acidic polysaccharide in the reactant are each within the range of 2 to 30% by mass.

[0025] In embodiments of the present invention, from the viewpoint of achieving the effects of the present invention, it is preferable that the total content of the mixture and the reactants relative to the total amount of the flame-retardant resin composition is within the range of 5 to 40% by mass.

[0026] In embodiments of the present invention, from the viewpoint of achieving the effects of the present invention, it is preferable that the flame-retardant resin composition further contains a phosphorus-based flame retardant in an amount of 1 to 20% by mass relative to the total amount of the flame-retardant resin composition. Phosphorus-based flame retardants, which are a type of general flame retardant, are thought to assist in the formation of a carbonized layer by converting phosphorus into phosphoric acid during combustion, and by promoting the dehydration reaction of this phosphoric acid. In other words, phosphorus-based flame retardants have the effect of promoting carbonization, similar to the acidic functional groups of acidic polysaccharides, and thus can work together to promote flame retardancy. In addition, since both phosphoric acid and polysaccharides can form hydrogen bonds, the intermolecular distances tend to be close, making it easier to obtain a more flame-retardant effect.

[0027] The flame-retardant resin housing of the present invention is a flame-retardant resin housing made using a flame-retardant resin composition, characterized in that the flame-retardant resin composition is the flame-retardant resin composition of the present invention.

[0028] The present invention, its components, and embodiments and models for carrying out the present invention will be described in detail below. In this application, "~" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0029] [Flame-retardant resin composition] The flame-retardant resin composition of the present invention is a flame-retardant resin composition containing a thermoplastic resin and a flame retardant, characterized in that the flame retardant contains a mixture of an acidic polysaccharide and a non-reactive organosilicon compound, which consists of one or more selected from a polysaccharide having an acidic functional group, a derivative of the acidic functional group having an acidic functional group modified while retaining at least a portion of the acidic functional group, and salts thereof, or a reaction product of a reactive organosilicon compound that is reactive with the acidic polysaccharide and the acidic polysaccharide.

[0030] Hereinafter, a mixture of acidic polysaccharides and non-reactive organosilicon compounds, and a reaction product of acidic polysaccharides and reactive organosilicon compounds (hereinafter also simply referred to as "reactive organosilicon compounds") are sometimes collectively referred to as "acidic polysaccharide-based flame retardants (A)." A mixture of acidic polysaccharides and non-reactive organosilicon compounds is also referred to as "mixture (A1)," and a reaction product of acidic polysaccharides and reactive organosilicon compounds (hereinafter also simply referred to as "reactive organosilicon compounds") is also referred to as "reactant (A2)."

[0031] The mixture (A1) may be incorporated into the flame-retardant resin composition as a mixture (A1) in which an acidic polysaccharide and a non-reactive organosilicon compound are pre-mixed, or the acidic polysaccharide and the non-reactive organosilicon compound may be incorporated into the flame-retardant resin composition separately and exist as a mixture (A1) within the flame-retardant resin composition.

[0032] The reactant (A2) may be incorporated into the flame-retardant resin composition as a reactant (A2) obtained by pre-reacting an acidic polysaccharide with a reactive organosilicon compound, or it may exist as a reactant (A2) obtained by separately incorporating the acidic polysaccharide and the reactive organosilicon compound into the flame-retardant resin composition and reacting within the flame-retardant resin composition. The reactant (A2) may contain unreacted raw materials, i.e., unreacted reactive organosilicon and acidic polysaccharides, along with the reaction product obtained by the actual reaction of the reactive organosilicon compound and the acidic polysaccharide. Furthermore, to the extent that the effects of the present invention are not impaired, the reactant (A2) may also contain by-products generated during the reaction.

[0033] The flame-retardant resin composition of the present invention contains a thermoplastic resin and an acidic polysaccharide-based flame retardant (A). In the flame-retardant resin composition of the present invention, the acidic polysaccharide-based flame retardant (A) functions as a flame retardant. In addition to the thermoplastic resin and the acidic polysaccharide-based flame retardant (A), the flame-retardant resin composition of the present invention may also contain other flame retardants, such as phosphorus-based flame retardants. Furthermore, the flame-retardant resin composition of the present invention may optionally contain various additives that are generally found in flame-retardant resin compositions. The components of the flame-retardant resin composition of the present invention will be described below.

[0034] (thermoplastic resin) The thermoplastic resin contained in the flame-retardant resin composition of the present invention can be any known thermoplastic resin without particular limitation. Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polycarbonate resins, aromatic polyester resins, polyphenylene sulfite resins, polyamide-imide resins, polyetheretherketone resins, polyethersulfone resins, polyimide resins, polyvinyl chloride resins, polyamide resins, polyacetal resins, acrylic resins, polystyrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, 1,2-polybutadiene-based thermoplastic elastomers, ethylene-vinyl acetate copolymer-based thermoplastic elastomers, fluororubber-based thermoplastic elastomers, and chlorinated polyethylene-based thermoplastic elastomers.

[0035] Furthermore, the thermoplastic resin contained in the flame-retardant resin composition of the present invention can be a thermoplastic resin that is generally treated as a biodegradable resin. Examples of biodegradable thermoplastic resins include aliphatic polyesters, polyamino acids, polyvinyl alcohol, polyalkylene glycols, and copolymers containing these. The thermoplastic resin may be one of the above resins used alone or two or more used in combination.

[0036] The above-mentioned polystyrene resins include polystyrene resin, syndiotactic polystyrene resin, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), and the like.

[0037] Aromatic polyester resins include aromatic polyesters having a structure in which an aromatic dicarboxylic acid or its ester derivative component is linked to a diol component such as an aliphatic diol or alicyclic diol by an ester reaction. Specifically, examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate, as well as copolymer polyesters such as polyethylene isophthalate / terephthalate, polybutylene terephthalate / isophthalate, and polybutylene terephthalate / decanedicarboxylate.

[0038] Examples of aliphatic polyesters, which are biodegradable thermoplastic resins, include polyoxy acids, which are (co)polymers of oxy acids, and polycondensates of aliphatic diols and aliphatic dicarboxylic acids. Examples of polyoxy acids include poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), random copolymers of L-lactic acid and D-lactic acid, stereocomplexes of L-lactic acid and D-lactic acid, polycaprolactone, polyhydroxybutyric acid, and polyhydroxyvaleric acid. Examples of polycondensates of aliphatic diols and aliphatic dicarboxylic acids include polyethylene succinate, polybutylene succinate (PBS), and polybutylene adipate.

[0039] Using biodegradable thermoplastic resins as thermoplastic resins is preferable from the viewpoint of reducing environmental impact. Furthermore, by combining biodegradable thermoplastic resins with non-biodegradable thermoplastic resins, a thermoplastic resin that combines the advantages of both can be obtained.

[0040] The thermoplastic resin content in the flame-retardant resin composition of the present invention is the amount obtained by subtracting the content of the acidic polysaccharide-based flame retardant (A) and other various additives optionally included in the flame-retardant resin composition.

[0041] (Acidic polysaccharide-based flame retardant (A)) The acidic polysaccharide-based flame retardant (A) consists of a mixture (A1) or a reactant (A2). The acidic polysaccharide-based flame retardant (A) may consist of mixture (A1) alone, reactant (A2) alone, or a combination of both.

[0042] <Mixture (A1)> Mixture (A1) is a mixture of acidic polysaccharides and non-reactive organosilicon compounds. The acidic polysaccharides contained in mixture (A1) consist of one or more selected from polysaccharides having acidic functional groups, their derivatives (provided that the derivatives are modified while retaining at least some of the acidic functional groups), and salts thereof.

[0043] In this specification, polysaccharides are a general term for substances formed by the dehydration condensation of numerous monosaccharide molecules via glycosidic bonds. The type of monosaccharide that makes up the polysaccharide is one or more. The monosaccharide is preferably a pentose or a hexose, and more preferably a hexose. The degree of polymerization of the polysaccharide is, for example, 50 to 20000, preferably 200 to 1500, and more preferably 200 to 1100.

[0044] A derivative of a polysaccharide having an acidic functional group is a derivative that has been modified while retaining at least some of the acidic functional groups of the polysaccharide. In this specification, unless otherwise specified, the term "derivative of a polysaccharide having an acidic functional group" is used in the sense described above. Examples of derivatives of polysaccharides having an acidic functional group include compounds obtained by replacing atoms bonded to the backbone of the polysaccharide with different atoms or substituents while retaining at least some of the acidic functional groups of the polysaccharide, and compounds obtained by bonding the polysaccharide's sugar chain to other compounds or other molecules of the polysaccharide via functional groups such as hydroxyl groups or some of the acidic functional groups originally present in the polysaccharide's sugar chain.

[0045] Examples of acidic functional groups found in acidic polysaccharides include carboxyl groups (-COOH), sulfol groups (-SO3H), thiocarboxyl groups (-CSOH), sulfino groups (-SO2H), and sulfeno groups (-SOH), with carboxyl groups and sulfol groups being preferred. The acidic functional group may also be an acidic functional group having a sulfol group, for example, an acidic functional group in which the sulfol group is bonded to an oxygen atom (-O-SO3H). Salts of the acidic functional group may include salts with alkali metals such as Li, Na, and K, salts with alkaline earth metals such as Mg, Ca, Sr, and Ba, and alkyl(ammonium) (e.g., R4N). + Examples include salts of the following: -(where R is independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, with at least one of R being an alkyl group.)

[0046] The molecular weight of the acidic polysaccharide is preferably in the range of 10,000 to 250,000, and more preferably in the range of 20,000 to 80,000, based on the weight-average molecular weight of polystyrene determined by gel permeation chromatography (GPC).

[0047] Examples of acidic polysaccharides include pectin, alginic acid, propylene glycol alginate, carboxymethylcellulose, xanthan gum, gum arabic, karaya gum, plantain, xylan, arabic acid, tragacanthic acid, khava gum, linseedic acid, cerulonic acid, lichenin uronic acid, gellan gum, ramsang gum, welan gum, carrageenan, glycosaminoglycans (e.g., hyaluronic acid, chondroitin-4 sulfate, chondroitin-6 sulfate, dermatan sulfate, keratin sulfate, and heparin) and their salts.

[0048] Among these, as acidic polysaccharides, at least one selected from alginic acid, alginate, carrageenan, pectin, xanthan gum, and gellan gum is preferred from the viewpoint of heat resistance stability when mixed in a flame-retardant resin composition. Among these, alginic acid and alginate are more preferred from the viewpoint of achieving both flame retardancy and heat resistance, divalent salts of alginic acid are even more preferred, and calcium alginate is particularly preferred.

[0049] Alginic acid is known as an intercellular polysaccharide found in the thallus of seaweed (brown algae), and is typically considered a naturally occurring compound obtained by industrial extraction and purification from the thallus. Alginic acid is a type of polysaccharide whose structure is represented by the following formula (1), consisting of repeating mannuronic acid units and guluronic acid units. In formula (1), the units enclosed in parentheses on the left are guluronic acid units, and the units enclosed in parentheses on the right are mannuronic acid units. Both guluronic acid and mannuronic acid are types of uronic acid. Guluronic acid and mannuronic acid are stereoisomers of each other, with guluronic acid being the L-form and mannuronic acid being the D-form.

[0050] [ka]

[0051] In equation (1), G represents the number of moles of guluronic acid units in the alginate skeleton, and M represents the number of moles of mannuronic acid units in the alginate skeleton. Note that equation (1) is an equation that shows the molar composition of each constituent unit in the compound, and does not show a structure in which a block of G moles of guluronic acid units and a block of M moles of mannuronic acid units are bonded together. In other words, equation (1) does not specify the bonding order of guluronic acid units and mannuronic acid units in the compound. The molar ratio (M / G ratio) of mannuronic acid units to guluronic acid units in the alginate shown in equation (1) is denoted as M / G.

[0052] In this specification, the terms "guluronic acid unit" and "mannuronic acid unit" include not only the guluronic acid unit and mannuronic acid unit shown in formula (1), but also units containing the guluronic acid skeleton and units containing the mannuronic acid skeleton in derivatives in which hydrogen atoms of each unit are substituted or substituents are introduced via hydroxyl or carboxyl groups. The same applies to salts of alginic acid or derivatives of alginic acid.

[0053] As described above, the order in which guluronic acid units and mannuronic acid units are bonded in formula (1) is not particularly limited. Glucuronic acid units and mannuronic acid units may be bonded randomly, blocks of guluronic acid units and blocks of mannuronic acid units may be bonded, or a combination thereof may be present. The alginic acid shown in formula (1) typically consists of blocks in which guluronic acid and mannuronic acid are bonded randomly (hereinafter also referred to as "MG blocks"), and combinations of blocks of guluronic acid units (hereinafter also referred to as "GG blocks") and blocks of mannuronic acid units (hereinafter also referred to as "MM blocks").

[0054] The regions where guluronic acid units are linked tend to have a denser molecular structure and are more easily crosslinked; therefore, the smaller the M / G ratio, the better the heat resistance. The M / G ratio of the alginic acid compounds according to the present invention is preferably 1.2 or less, more preferably 1.0 or less, and even more preferably 0.6 or less. The lower limit of the M / G ratio is 0. An M / G ratio of 0 means that all the constituent units of the alginic acid compounds are composed of guluronic acid units.

[0055] Here, alginic acid derivatives are typically of natural origin, and their M / G ratio varies depending on the type of seaweed (brown algae), origin, season, and even the part of the thallus. By strictly selecting appropriate raw seaweed and industrially extracting and purifying it, alginic acid derivatives with different M / G ratios can be produced. Since the M / G ratio of alginic acid derivatives is adjusted in this way, considering factors such as availability (including cost) and environmental impact, the lower limit of the M / G ratio is preferably around 0.3, and more preferably around 0.4.

[0056] The M / G ratio of alginates can be measured using the method described, for example, in "On the Raw Material Properties of Unutilized Brown Algae" (Research Report of Hokkaido Prefectural Fisheries Experiment Station, No. 57, 15-22 (2000), Akiko Miyazaki et al.).

[0057] For alginate derivatives and salts of alginic acid or its derivatives, the M / G ratio can also be measured by the same method as described above. Also, since the M / G ratio of an alginate derivative obtained from alginic acid with a known M / G ratio and salts of alginic acid or its derivatives does not change from the M / G ratio of the original alginic acid, the M / G ratio of the original alginic acid can be used as it is.

[0058] In addition, in alginic acid or its derivatives, when the part where guluronic acid units are linked forms a divalent salt, it tends to form a dense intermolecular cross-linked structure centered on ions called the egg box structure. Part of the intermolecular cross-linked structure of the part where guluronic acid units of calcium alginate are linked is shown in the following formula (3).

[0059]

Chemical formula

[0060] Formula (3) shows two adjacent molecular chains (molecular chain (I) and molecular chain (II)), and shows the parts where four guluronic acid units are linked respectively. In molecular chain (I) and molecular chain (II)), the guluronic acid units are bent and connected, and COO - exists on both sides of the molecular chain (for convenience, one side is distinguished as the "upper side" and the other side as the "lower side" from the visual position of formula (3)). In formula (3), the COO - on the lower side of molecular chain (I) and the COO - on the upper side of molecular chain (II) form a salt through Ca 2+ , thereby cross-linking molecular chain (I) and molecular chain (II).

[0061] Although not shown in formula (3), the COO - on the upper side of molecular chain (I) and the COO - on the lower side of molecular chain (II) each form a salt through Ca 2+ with the COO - of another molecular chain and are cross-linked. The intermolecular cross-linked structure formed in this way is said to particularly improve thermal stability and effectively suppress coloring during molding.

[0062] Acidic polysaccharides may be used individually or in combination of two or more types.

[0063] In mixture (A1), the non-reactive organosilicon compounds used together with the acidic polysaccharides include, without particular limitation, various organosilicon compounds that do not have reactive functional groups, and especially those that do not have functional groups that are reactive with acidic polysaccharides.

[0064] Specifically, examples include non-reactive silicone oils and non-reactive silazane compounds, with non-reactive silicone oils being preferred.

[0065] Examples of non-reactive silicone oils include polymer compounds having a main skeleton of siloxane bonds, in which non-reactive organic groups are bonded to silicon atoms. Typical examples of non-reactive silicone oils include compounds whose structure is represented by the following formula (4).

[0066] [ka]

[0067] In formula (4), R 2 These independently represent monovalent, unsubstituted hydrocarbon groups (but without aliphatic unsaturated groups), and R 1 R is independent of each other. 2 This indicates a monovalent hydrocarbon group having the specified group or a non-reactive substituent. m and n represent the number of repeating units enclosed in parentheses, respectively. m is an integer of 1 or more, and n is 0 or an integer of 1 or more. m+n is the range in which the oil properties can be maintained. Specifically, maintaining oil properties means that the kinematic viscosity (25°C) is between 1 and 20000 mmHg. 2 This refers to a range of approximately / s.

[0068] R 2Examples include alkyl groups with linear, branched, cyclic, or combinations thereof, having 1 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms; and aralkyl groups with 7 to 20 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, and dodecyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; and aralkyl groups such as 2-phenylethyl and 2-phenylpropyl groups.

[0069] R 1 For example, the above R 2 Examples include the groups shown and groups in which these are substituted with non-reactive substituents. Non-reactive substituents include halogen atoms (chloro group, fluoro group, bromo group, etc.) and polyether groups (for example, -(C) x H 2x O) a R 12 x is an integer between 2 and 6, and a is an integer greater than or equal to 1. If a is 2 or greater, the number of units of x may be different, for example, a combination of a unit where x is 2 and a unit where x is 3. ), polyester group (-OCOR 12 ), polyamide group (-NHCOR 12 ), -Si(R 12 )2OSiR 12 Third place is mentioned. Note that R in each formula 12 The above R 2 It can be a group similar to the one shown. 1 This is a polyester group (-OCOR) that is directly bonded to a silicon atom. 12 ) is also acceptable.

[0070] A typical compound shown in formula (4) is R 1 and R 2 Dimethylpolysiloxane, where all are methyl groups, R 2 All of them are methyl groups, R 1 At least one of them is a R other than a methyl group. 2 The base R, which was used as an example, 2 Examples include compounds in which the group is substituted with a non-reactive substituent or a polyester group.

[0071] More specifically, dimethylpolysiloxane, with R at both ends 1 and R 2 All of them are methyl groups and the R in the side chain 1 These include long-chain alkyl groups (6-20 carbon atoms), phenyl groups, 2-phenylpropyl groups, fluoroalkyl groups (e.g., -CH2CH2CF3), and polyether groups (e.g., -R 11 (C2H4O) a1 (C3H6O) a2 R 12 ), polyester group (-OCOR 12 ), polyamide group (-R 11 NHCOR 12 ), -R 11 Si(R 12 )2OSiR 12 A compound selected from 3, and the R of the side chain 1 and R 2 All of them are methyl groups and both terminal R 1 is a polyether group (for example, -R 11 (C2H4O) a1 (C3H6O) a2 R 12 Examples include compounds such as ). Here, the R of the side chain 1 If R is one of the above groups, 1 There may be one type or two or more types. Also, R in each formula 11 The above R 2 This is a divalent group in which a hydrogen atom is missing from the group shown.

[0072] Non-reactive silicone oils can be used individually or in combination of two or more types. Commercially available non-reactive silicone oils can be used. Examples of commercially available products include, for example, KF-96 (dimethyl silicone oil), KF-50, KF-54 (all methylphenyl silicone oils), KF-351A, KF-352A, KF-6011, KF-6012, X-22-2516 (all polyether-modified silicone oils), KF-410 (aralkyl-modified silicone oil), X-22-821, FL-100 (all fluoroalkyl-modified silicone oils), KF-412, KF-413, X-22-7322, X-22-1877 (all long-chain alkyl-modified silicone oils), X-22-715 (higher fatty acid ester-modified silicone oil), KF-3935 (higher fatty acid amide-modified silicone oil), and KF-6004 (both-end polyether-modified silicone oil), all manufactured by Shin-Etsu Chemical Co., Ltd.

[0073] Although non-reactive silicone oils have been described above using compounds with the structure shown in formula (4) as an example, the non-reactive silicone oils used in the present invention are not limited to these, and cyclic silicone oils, three-dimensionally bonded silicone oils, etc., can also be used as long as they are non-reactive.

[0074] In mixture (A1), the proportion of the non-reactive organosilicon compound to the acidic polysaccharide is preferably in the range of 2 to 30% by mass, and more preferably in the range of 5 to 25% by mass. When the proportion of the non-reactive organosilicon compound to the acidic polysaccharide is within the above range, the colorability and impact strength of the molded article are further improved.

[0075] <Reactant (A2)> Reactant (A2) is the reaction product of an acidic polysaccharide and a reactive organosilicon compound. The acidic polysaccharide can be the same as that described in mixture (A1). The reactive organosilicon compound is an organosilicon compound having a functional group that is reactive with the acidic polysaccharide. As described above, reactant (A2) may consist only of the reaction product obtained by the actual reaction of the reactive organosilicon compound and the acidic polysaccharide, or it may also contain unreacted raw materials, i.e., unreacted reactive organosilicon compound and acidic polysaccharide, in addition to the reaction product. Furthermore, reactant (A2) may also contain by-products generated during the reaction, to the extent that it does not impair the effects of the present invention.

[0076] Reactive functional groups in reactive organosilicon compounds include hydroxyl groups or groups that react to acidic functional groups of acidic polysaccharides, such as amino groups, epoxy groups, carbinol groups, mercapto groups, silanol groups, hydrolyzable silyl groups, carboxyl groups, phenol groups, hydrosilyl groups, and acid anhydride groups. Among these, silanol groups, hydrolyzable silyl groups, and hydrosilyl groups are preferred.

[0077] Furthermore, a silanol group is a group in which 1 to 3 hydroxyl groups are bonded to a silicon atom, a hydrolyzable silyl group is a group in which 1 to 3 hydrolyzable groups are bonded to a silicon atom, and a hydrosilyl group is a group in which 1 to 3 hydrogen atoms are bonded to a silicon atom. The bonds of silicon atoms that are not bonded to hydroxyl groups, hydrolyzable groups, or hydrogen atoms are bonded to other groups such as -O-Si or hydrocarbon groups.

[0078] As reactive organosilicon compounds, specifically, reactive silicone oils and silane coupling agents are preferred. Examples of reactive silicone oils include compounds having the structure shown in the following formula (5).

[0079] [ka]

[0080] In formula (5), R 2 and R1 R in equation (4) 2 and R 1 It has the same meaning as R 3 R 2 or R 1 The group shown is a monovalent hydrocarbon group having a hydrogen atom, a hydroxyl group, a hydrolyzable group, or a reactive substituent, and at least one of them is a monovalent hydrocarbon group having a hydrogen atom, a hydroxyl group, a hydrolyzable group, or a reactive substituent. m, n, and p each indicate the number of repeating units enclosed in parentheses. m is an integer of 1 or more, and n and p are 0 or integers of 1 or more. m+n+p is the range in which the properties of the oil can be maintained.

[0081] R when it is reactive 3 Specifically, hydrogen atoms, hydroxyl groups, hydrolyzable groups, carbinol groups (-R 14 OH;R 14 (These are divalent aliphatic saturated hydrocarbon groups) and amino groups (-NR) 13 2;R 13 R is a hydrogen atom. 2 Similar to the base or -R 11 NR 13 2 (R 11 This has the same meaning as above.) Examples include hydrocarbon groups containing epoxy groups (including alicyclic epoxy groups), mercapto groups, silanol groups, hydrolyzable silyl groups, carboxyl groups, phenol groups, hydrosilyl groups, or acid anhydride groups. 3 Preferably, the group consists of a hydrogen atom, a hydroxyl group, a hydrolyzable group, or a hydrocarbon group having a silanol group, a hydrolyzable silyl group, or a hydrosilyl group.

[0082] Examples of the hydrolyzable group include an alkoxy group, a halogen atom, an acyl group, an isocyanate group, an amino group, and a group in which at least one hydrogen of the amino group is substituted with an alkyl group. From the viewpoint that the reaction proceeds smoothly to form a hydroxyl group (silanol group) by hydrolysis and further undergoes dehydration condensation with an acidic polysaccharide, an alkoxy group or a halogen atom is preferred. As the halogen atom, a chlorine atom is preferred. As the alkoxy group, an alkoxy group having 1 to 4 carbon atoms is preferred, and a methoxy group or an ethoxy group is more preferred. As the hydrolyzable group, a methoxy group or an ethoxy group is particularly preferred.

[0083] Examples of the hydrocarbon group having a hydrolyzable silyl group include, for example, -R 11 SiR 12 3-q X q where R <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​R when it is reactive 3 Examples include compounds in which a group is selected from the functional groups described above.

[0085] In reactive silicone oils, the content of reactive functional groups is, for example, in methyl hydrogen silicone oil (formula (5), R at both ends). 3 , R 2 and R 1 All of them are methyl groups, and the R in the side chain 3 For compounds where R is a hydrogen atom, an example of the equivalent amount of hydrogen atoms bonded to the silicon atom is 50 to 300 g / mol. Furthermore, in reactive silicone oils in which alkoxy groups bonded to silicon atoms are introduced into dimethyl silicone oil, for example, in formula (5), both ends of R 3 , R 2 and R 1 All of them are methyl groups, and the R in the side chain 3 ga-(CH2) n1 -Si(O(CH2) n2 Examples of equivalent amounts of the alkoxy group in a compound of CH3)3 (where n1 is an integer from 1 to 4 and n2 is 0 or 1) include 100 to 100,000 g / mol.

[0086] Reactive silicone oils can be used individually or in combination of two or more types. Commercially available reactive silicone oils can be used. Examples of commercially available products include, for example, KF-99, KF-9901 (both methyl hydrogen silicone oils), KF-868, KF-859, KF-8004, KF-8021, X-22-3939A, KF-8010 (all amino-modified silicone oils), KF-101, KF-1001, X-22-343, X-22-2000, KF-102, X-22-4741, X-22-163 (all, Examples include epoxy-modified silicone oil, X-22-4039, KF-6000 (all carbinol-modified silicone oils), KF-2001, X-22-167B (all mercapto-modified silicone oils), X-22-3701E, X-22-162C (all carboxy-modified silicone oils), X-21-5841 (silanol-terminated silicone oil), and X-22-168AS (carboxylic acid anhydride-modified silicone oil).

[0087] Examples of commercially available reactive silicone oils, in which alkoxy groups bonded to silicon atoms are introduced into dimethyl silicone oil, include KF-9908 (triethoxysilylethyl polydimethylsiloxyethyl dimethicone), whose structure is shown in formula (6) below, and KF-9909 (triethoxysilylethyl polydimethylsiloxyethyl hexyl dimethicone), both manufactured by Shin-Etsu Chemical Co., Ltd., whose structure is shown in formula (7) below. In formulas (6) and (7), x, y, z, and w are each integers of 1 or more.

[0088] [ka]

[0089] The reactive silicone oil described above uses the compound shown in formula (5) as an example, but the reactive silicone oil used in the present invention is not limited to this, and any reactive silicone oil, such as cyclic silicone oil or three-dimensionally bonded silicone oil, can also be used.

[0090] Silane coupling agents are compounds having a structure in which a hydrolyzable group is bonded to a silicon atom. For example, the compound shown in formula (6) below or its partially hydrolyzed condensate can be cited. The molecular weight of the silane coupling agent is preferably, for example, about 120 to 10000.

[0091] Formula (8) R 6 4-t -Si-X t

[0092] In formula (8), R 6 R is a monovalent organic group, and X is a hydrolyzable group. t is an integer from 1 to 4, preferably 1 to 3, and more preferably 3. 6 If there are multiple instances of and X, they may be identical or different from one another. The hydrolyzable groups are the same as those described above, including preferred embodiments.

[0093] R 6 This may be a non-reactive monovalent organic group, or a monovalent organic group having a reactive functional group. 6 Examples of reactive functional groups that may be present include vinyl groups, epoxy groups, styryl groups, methacryloxy groups, acryloxy groups, amino groups, isocyanate groups, mercapto groups, acid anhydride groups, isocyanurate groups, and ureido groups.

[0094] R is an unreactive organic group. 6 Examples include alkyl groups with linear, branched, cyclic, or combinations thereof, having 1 to 20 carbon atoms; aryl groups with 6 to 20 carbon atoms; and aralkyl groups with 7 to 20 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, and dodecyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; and aralkyl groups such as 2-phenylethyl and 2-phenylpropyl groups.

[0095] Among monovalent organic groups having reactive functional groups, for example, vinyl groups and styryl groups may be directly bonded to silicon atoms, or they may be bonded to silicon atoms via divalent linking groups. Groups other than vinyl and styryl groups exemplified above are typically bonded to silicon atoms via divalent linking groups. Examples of divalent linking groups include divalent hydrocarbon groups that may have an oxygen atom between carbon atoms, such as (CH2) y -(where y is an integer between 1 and 10) is preferred.

[0096] Furthermore, the silane coupling agent has a hydrolyzable silyl group at the end of the side chain of a compound having a main chain formed of carbon atoms, for example, the -R mentioned above. 11 SiR 12 3-q X q This includes compounds into which the group shown by is introduced. The main chain may be, for example, a main chain consisting of a divalent group represented by the following formulas (9) or (10) as repeating units. The main chain may consist only of the repeating units of formula (9), only of the repeating units of formula (10), or of both repeating units.

[0097] Formula (9) -CH2-CH2- Equation (10) -CH2-CH=CH-CH2-

[0098] In formula (9) or formula (10), at least one hydrogen atom of the -CH2- is substituted with a group having a hydrolyzable silyl group at its terminus to form a silane coupling agent. The other hydrogen atoms bonded to the -CH2- are monovalent hydrocarbon groups which may have substituents, for example, R 2 It may be substituted with a similar group. A substituent could be R 1 The substituents may also be nonreactive substituents as described above, R 3 The substituents may be those of the reactive type described above. The silane coupling agent may have multiple repeating units of formula (9) or multiple repeating units of formula (10), as long as it has a unit having a hydrolyzable silyl group.

[0099] Silane coupling agents can be used individually or in combination of two or more of these agents. Commercially available silane coupling agents can be used. Silane coupling agents may also be used as partial hydrolysis (co)condensates of one or more of these agents.

[0100] Examples of silane coupling agents include alkylsilanes such as methyltrimethoxysilane (KBM-13), dimethyldimethoxysilane (KBM-22), phenyltrimethoxysilane (KBM-103), n-propyltrimethoxysilane (KBM-3033), n-hexyltrimethoxysilane (KBM-3063), n-octyltrimethoxysilane, n-decyltrimethoxysilane (KBM-3103C), methyltriethoxysilane (KBE-13), dimethyldiethoxysilane (KBE-22), phenyltriethoxysilane (KBE-103), n-propyltriethoxysilane (KBE-3033), n-hexyltriethoxysilane (KBE-3063), n-octyltriethoxysilane (KBE-3183), and n-decyltriethoxysilane. The product name of the commercially available version (all manufactured by Shin-Etsu Chemical Co., Ltd.) is indicated in parentheses after the compound name. The same applies hereafter.

[0101] In addition, silane coupling agents having reactive functional groups other than hydrolyzable groups include vinyltrimethoxysilane (KBM-1003), vinyltriethoxysilane (KBE-1003), 7-octenyltrimethoxysilane (KBM-1083), 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (KBM-303), 3-glycidoxypropylmethyldimethoxysilane (KBM-402), 3-glycidoxypropyltrimethoxysilane (KBM-403), 3-glycidoxypropylmethyldiethoxysilane (KBE-402), 3-glycidoxypropyltriethoxysilane (KBE-403), 8-glycidoxyoctylmethoxysilane (KBM-4803), p-styryltrimethoxysilane (KBM-1403), and 3-methacryloxy Propylmethyldimethoxysilane (KBM-502), 3-methacryloxypropyltrimethoxysilane (KBM-503), 3-methacryloxypropylmethyldiethoxysilane (KBE-502), 3-methacryloxypropyltriethoxysilane (KBE-503), 8-methacryloxyoctylmethoxysilane (KBM-5803), 3-acryloxypropyltrimethoxysilane (KBM-5103), N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM-602), N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (KBM-603), 3-aminopropyltrimethoxysilane (KBM-903), 3-aminopropyltriethoxysilane (KBE-903), 3-triethoxysilyl-N-(1,Examples include 3-dimethylbutylidene)propylamine (KBE-9103P), N-phenyl-3-aminopropyltrimethoxysilane (KBM-573), hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane (KBM-575), N-2-(aminoethyl)-8-aminooctyltrimethoxysilane (KBM-6803), tris-(trimethoxysilylpropyl)isocyanurate (KBM-9659), 3-ureidopropyltrialkoxysilane (KBE-585A), 3-mercaptopropylmethyldimethoxysilane (KBM-802), 3-mercaptopropyltrimethoxysilane (KBM-803), 3-isocyanatetopropyltriethoxysilane (KBE-9007N), and 3-trimethoxysilylpropyl succinic anhydride (X-12-967C).

[0102] Examples of silane coupling agents having a hydrolyzable silyl group at the end of the side chain of a compound having a main chain formed of carbon atoms include compounds whose structure is represented by the following formulas (11) or (12). In formulas (11) and (12), Me is a methyl group and Et is an ethyl group. a, b, c, e, g, and h are each integers of 1 or more. Examples of commercially available products include X-12-1287A as a silane coupling agent of formula (11) and X-12-1281A as a silane coupling agent of formula (12), both manufactured by Shin-Etsu Chemical Co., Ltd.

[0103] [ka]

[0104] As the reactive organosilicon compound, one of the compounds exemplified above may be used alone, or two or more may be used in combination. The ratio of the reactive organosilicon compound to the acidic polysaccharide in the reaction product (A2) is preferably in the range of 2 to 30% by mass, and more preferably in the range of 5 to 20% by mass. When the ratio of the reactive organosilicon compound to the acidic polysaccharide is within the above range, the colorability and impact strength of the molded product are further improved.

[0105] The above ratio is calculated from the total amount of reaction products and unreacted raw materials contained in reactant (A2). For example, if reactant (A2) is obtained by reacting an acidic polysaccharide with a reactive organosilicon compound and then isolating only the reaction product, i.e., if it consists only of the reaction product, the above ratio is calculated by analyzing the chemical structure of the reaction product and determining the amount of the portion derived from the acidic polysaccharide and the portion derived from the reactive organosilicon compound.

[0106] If the reactant (A2) is obtained by reacting an acidic polysaccharide with a reactive organosilicon compound and then removing the solvent, etc., i.e., if it consists of a reaction product and unreacted raw materials, the above ratio is calculated from the amount of each component in the reaction product and the amount of unreacted components. Furthermore, if the reactant (A2) is obtained by separately adding an acidic polysaccharide and a reactive organosilicon compound to a flame-retardant resin composition and reacting them during the production of the composition, the ratio is calculated as the ratio of the amount of reactive organosilicon compound to the amount of separately added acidic polysaccharide.

[0107] With respect to the reactant (A2), when the acidic polysaccharide and reactive organosilicon compound are reacted before being incorporated into the flame-retardant resin composition, the reaction can be carried out by, for example, the following methods (i) to (iii), with method (i) being preferred. The acidic polysaccharide and reactive organosilicon compound used in the reaction may be one type each, or two or more types.

[0108] (i) A wet method in which an acidic polysaccharide and a reactive organosilicon compound are dispersed in a solvent and reacted under predetermined conditions. (ii) Dry method: Mixing an acidic polysaccharide with a reactive organosilicon compound or a reactive organosilicon compound dissolved in a small amount of solvent and reacting them. (iii) A method of reacting by spraying an acidic polysaccharide and a reactive organosilicon compound into the air and mixing them.

[0109] The crude reaction product obtained by the above method contains, in addition to the reaction product resulting from the actual reaction of the acidic polysaccharide and the reactive organosilicon compound, unreacted raw materials, i.e., unreacted reactive organosilicon compound, acidic polysaccharide, and by-products. As long as the by-product content in the crude reaction product is within a range that does not impair the effects of the present invention, the crude reaction product may be used as is as reactant (A2), or the crude reaction product from which the by-products have been removed may be used as reactant (A2). Alternatively, only the reaction product may be isolated from the crude reaction product and used as reactant (A2).

[0110] The acidic polysaccharide-based flame retardant (A) may be one of the mixture (A1) and reactant (A2) described above, or two or more may be used in combination. In the case of two or more, it may be two or more of the mixture (A1), two or more of the reactant (A2), or two or more combinations of the mixture (A1) and reactant (A2). In the flame-retardant resin composition of the present invention, the content of the acidic polysaccharide-based flame retardant (A) is preferably in the range of 5 to 40% by mass, and more preferably in the range of 20 to 30% by mass, relative to the total amount of the flame-retardant resin composition. If the content of the acidic polysaccharide-based flame retardant (A) in the flame-retardant resin composition is within the above range, flame retardancy, colorability, and impact strength can be well balanced in the resulting molded article.

[0111] (Phosphorus-based flame retardant) The flame-retardant resin composition of the present invention preferably contains a phosphorus-based flame retardant in addition to the acidic polysaccharide-based flame retardant (A). As described above, the phosphorus-based flame retardant has the effect of assisting in the formation of the carbonized layer of the acidic polysaccharide-based flame retardant (A), and can further shorten the intermolecular distance by forming hydrogen bonds, so the combined effect of the two can further promote flame retardancy.

[0112] The content of the phosphorus-based flame retardant is preferably in the range of 1 to 20% by mass, more preferably in the range of 2 to 15% by mass, and even more preferably in the range of 3 to 10% by mass, based on the total amount of the flame-retardant resin composition of the present invention.

[0113] If the phosphorus-based flame retardant content is within the above range, a sufficient amount of the acidic polysaccharide-based flame retardant (A) can be ensured, and flame retardancy in the resulting molded product can be enhanced without impairing the effect of the acidic polysaccharide-based flame retardant (A). Furthermore, if the content is below the above upper limit, it is easier to suppress the reduction in strength of the molded product due to the inclusion of the phosphorus-based flame retardant.

[0114] Furthermore, depending on the type of thermoplastic resin it is combined with, phosphorus-based flame retardants tend to separate during melting, and the separated material may bleed out and remain on the surface of the molded product, leading to a deterioration in appearance. If the content of phosphorus-based flame retardants is 20% by mass relative to the total amount of the flame retardant resin composition, the deterioration in appearance caused by the bleeding out of phosphorus-based flame retardants can be suppressed.

[0115] Examples of phosphorus-based flame retardants include phosphinic acid, phosphonic acid, salts with metals such as phosphoric acid and ammonium, and ester compounds of phosphinic acid, phosphonic acid, and phosphoric acid. Among these, phosphorus ester compounds (described in detail later) are preferred as phosphorus-based flame retardants from the viewpoint of flame retardant effect.

[0116] Specifically, the above-mentioned salts include phosphinate metal salts, particularly aluminum phosphinate and zinc phosphinate; phosphonate metal salts, particularly aluminum phosphonate, calcium phosphonate, and zinc phosphonate; and hydrates of equivalent phosphonate metal salts, ammonium phosphate, and ammonium polyphosphate.

[0117] Examples of phosphinic acid ester compounds include dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, and bis(4-methoxyphenyl)phosphinic acid.

[0118] Examples of phosphonic acid ester compounds include methylphosphonic acid, dimethyl methylphosphonic acid, diethyl methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, 2-methyl-propylphosphonic acid, t-butylphosphonic acid, 2,3-dimethylbutylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, and dioctylphenylphosphonate.

[0119] In addition, as phosphorus-based flame retardants other than those mentioned above, derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO), polyphosphonates (e.g., Nofia® HM1100 (manufactured by FRXPolymers (Chelmsford, USA))), zinc bis(diethylphosphinate), aluminum tris(diethylphosphinate), melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine poly(aluminum phosphate), melamine poly(zinc phosphate), methylphosphonate melamine salt, guanylurea phosphate, guanidine phosphate, ethylenediamine phosphate, and phosphazene compounds, such as phenoxyphosphazene oligomers, may be used as phosphorus-based flame retardants.

[0120] Phosphorus-based flame retardants may be used individually or in combination of two or more types.

[0121] [Phosphate ester compounds] The phosphate ester compound may be either an aliphatic phosphate ester compound or an aromatic phosphate ester compound, with aromatic phosphate ester compounds being preferred. Using an aromatic phosphate ester compound as a phosphorus-based flame retardant allows for mixing and molding at lower temperatures and with lower shear, and suppresses thermal decomposition of the acidic polysaccharide-based flame retardant (A) during mixing and molding, which can lead to discoloration and foaming. Furthermore, it is expected that decomposition at high temperatures during ignition will generate phosphoric acid, which will promote the carbonization of the acidic polysaccharide-based flame retardant (A), making it easier to exhibit flame retardant effects.

[0122] Examples of phosphate ester compounds include monomeric phosphate ester compounds obtained by reacting phosphoric acid with aliphatic or aromatic alcohols, and aromatic condensed phosphate ester compounds which are reaction products of phosphorus oxychloride with a divalent phenolic compound and phenol (or alkylphenol).

[0123] Phosphate ester compounds specifically include trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate, triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), tris(2,4-di-t-butylphenyl) phosphate, distearyl pentaerythritol diphosphate, bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphate, bis(2,4-di-t-butylphenyl) pentaerythritol diphosphate, resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), bisphenol A bis-dicresyl phosphate, biphenol A bis-diphenyl phosphate, and biphenol A bis-dixylenyl phosphate.

[0124] Furthermore, from the viewpoint of heat resistance and other factors, the phosphate ester compound is preferably a condensed phosphate ester compound of the condensation type. Examples of condensed phosphate ester compounds include aromatic condensed phosphate ester compounds represented by the following chemical formula (P).

[0125] [ka]

[0126] In the above formula (P), R 1 ~R 5 Each of these is independently a hydrogen atom, a C1-C10 alkyl group, a C3-C20 cycloalkyl group, a C6-C20 aryl group, or a C1-C10 alkoxy group, and R 1 ~R5 They may be the same or different. There can be multiple (5) Rs. 1 These elements may be identical or different from each other. There may be multiple (4-5) of each R. 2 , R 3 , R 4 and R 5 The same applies to n. n is an integer from 1 to 30, preferably an integer from 1 to 10.

[0127] Examples of the alkyl groups mentioned above include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, amyl group, tert-amyl group, hexyl group, 2-ethylhexyl group, n-octyl group, nonyl group, decyl group, and the like.

[0128] Examples of the above cycloalkyl groups include cyclohexyl groups. Examples of the above aryl groups include phenyl groups, cresyl groups, xylyl groups, 2,6-xylyl groups, 2,4,6-trimethylphenyl groups, butylphenyl groups, and nonylphenyl groups.

[0129] Examples of the alkoxy groups mentioned above include methoxy groups, ethoxy groups, propoxy groups, and butoxy groups.

[0130] Aromatic condensed phosphate ester compounds are reaction products of phosphorus oxychloride, a divalent phenolic compound, and phenol (or alkylphenol), as described above. The aromatic condensed phosphate ester compound represented by formula (P) is a compound in which the divalent phenolic compound is resocinol (hereinafter also referred to as "resosinol compound") which may have substituents. The aromatic condensed phosphate ester compound may also be a compound obtained by using 4,4'-biphenol or bisphenol A (each of which may have substituents) instead of the resocinol compound. Specifically, in formula (P), aromatic condensed phosphate ester compounds having a 4,4'-biphenol residue or a bisphenol A residue, each of which may have substituents, instead of the resocinol compound residue can be used in the present invention.

[0131] Commercially available phosphate ester compounds may be used. Examples of commercially available phosphate ester compounds that can be used include PX-200 (resorcinol bis-dixylenyl phosphate), CR-733S (resorcinol bis-diphenyl phosphate), and CR-741 (bisphenol A bis(diphenyl phosphate)), all manufactured by Daihachi Chemical Industry Co., Ltd.

[0132] (Other flame retardants) The flame-retardant resin composition of the present invention contains an acidic polysaccharide-based flame retardant (A) as a flame retardant. The flame retardant may optionally contain a phosphorus-based flame retardant, and may also contain other flame retardants other than the acidic polysaccharide-based flame retardant (A) and the phosphorus-based flame retardant (also simply referred to as "other flame retardants"), as long as the effects of the present invention are not impaired. Examples of other flame retardants include polysaccharides other than the acidic polysaccharide-based flame retardant (A), metal hydroxides, and intomescent flame retardants.

[0133] If the above-mentioned flame retardant contains metal hydroxides as other flame retardants, the content is preferably in the range of 5 to 20% by mass, and more preferably in the range of 5 to 10% by mass, relative to the total amount of the flame retardant resin composition. If the content of metal hydroxides in the flame retardant resin composition is within the above range, it is easier to achieve a higher level of balance between the development of flame retardancy and the maintenance of strength in the resulting molded article.

[0134] Examples of the above-mentioned metal hydroxides include aluminum hydroxide and magnesium hydroxide, with aluminum hydroxide being particularly preferred.

[0135] The form of the metal hydroxide described above is preferably particles. The particle shape is not particularly limited and can be spherical, spindle-shaped, plate-shaped, flake-shaped, needle-shaped, fibrous, etc. Furthermore, the average primary particle diameter of the metal hydroxide particles is preferably in the range of 10 nm to 100 μm, and more preferably in the range of 10 to 100 nm. The average primary particle diameter of the metal hydroxide particles is, for example, the volume-based median diameter (D50). The volume-based median diameter (D50) can be measured, for example, by laser diffraction / scattering using a laser detector such as the LA-960S2 (manufactured by HORIBA).

[0136] The metal hydroxide particles described above may be surface-modified with a surface modifier as needed. Suitable surface modifiers include alkylsilazane compounds such as hexamethyldisilazane (HMDS), alkylalkoxysilane compounds such as dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, and butyltrimethoxysilane, chlorosilane compounds such as dimethyldichlorosilane and trimethylchlorosilane, silicone oils, silicone varnishes, and various fatty acids. These surface modifiers may be used individually or in combination of two or more.

[0137] (Other additives) Other additives that may be optionally included in the flame-retardant resin composition of the present invention include antioxidants, fillers, and nucleating agents. The content of other additives in the flame-retardant resin composition of the present invention is within a range that does not impair the effects of the present invention, and for example, is in the range of 0 to 30% by mass of the total amount of the flame-retardant resin composition, preferably in the range of 0 to 20% by mass. Furthermore, a total of 30% by mass or less is preferred.

[0138] (Manufacturing of flame-retardant resin compositions) The flame-retardant resin composition of the present invention can be obtained by melt-kneading a thermoplastic resin, an acidic polysaccharide-based flame retardant (A), and optionally a phosphorus-based flame retardant, other flame retardants, and other additives. The method of melt-kneading is not particularly limited, and known melt-kneading methods can be used.

[0139] Specific examples include a method in which each component is pre-mixed using various mixers such as tumblers or high-speed mixers known as Henschel mixers, and then melt-kneaded using kneading equipment such as Banbury mixers, rolls, plastographs, single-screw extruders, twin-screw extruders, and kneaders. Among these, the manufacturing method using an extruder for melt-kneading is more preferable due to its high production efficiency, and the manufacturing method using a twin-screw extruder is even more preferable. After melt-kneading each component using an extruder and extruding the kneaded material into strands, the extruded strands can be processed into pellets, flakes, or other forms.

[0140] Furthermore, if the acidic polysaccharide-based flame retardant (A) is a mixture (A1), it may be incorporated into the flame retardant resin composition as a mixture (A1) in which the acidic polysaccharide and the non-reactive organosilicon compound are pre-mixed, or the acidic polysaccharide and the non-reactive organosilicon compound may be incorporated into the flame retardant resin composition separately. In that case, the timing at which the acidic polysaccharide and the non-reactive organosilicon compound are added to the components of the flame retardant resin composition other than the acidic polysaccharide-based flame retardant (A) may be simultaneous or different. It is preferable to add the non-reactive organosilicon compound first, followed by the acidic polysaccharide.

[0141] When the acidic polysaccharide-based flame retardant (A) is a reactant (A2), it may be incorporated into the flame-retardant resin composition as a reactant (A2) obtained by pre-reacting the acidic polysaccharide with a reactive organosilicon compound, or it may be in the form of a reactant (A2) obtained by separately incorporating the acidic polysaccharide and the reactive organosilicon compound into the flame-retardant resin composition and reacting within the flame-retardant resin composition. In that case, the timing at which the acidic polysaccharide and the reactive organosilicon compound are added to the components other than the acidic polysaccharide-based flame retardant (A) contained in the flame-retardant resin composition may be simultaneous or different. It is preferable to add the reactive organosilicon compound first, followed by the acidic polysaccharide.

[0142] Furthermore, when using a combination of mixture (A1) and reactant (A2), the same methods as those described above for adding each component can be followed. For example, mixture (A1) and reactant (A2) may be added simultaneously or separately. Alternatively, the components constituting mixture (A1) and reactant (A2) may be added sequentially. When adding sequentially, it is preferable to add the acidic polysaccharide last.

[0143] It is preferable to thoroughly dry each component before pre-mixing. The drying temperature is not particularly limited, but is preferably 60 to 100°C. The drying time is also not particularly limited, but is preferably 2 to 6 hours. Furthermore, drying under reduced pressure is preferable as it facilitates the drying process. Alternatively, the above drying process may be repeated after pre-mixing.

[0144] The temperature during melt mixing is, for example, 150 to 280°C, and is appropriately selected depending on the type and content of the thermoplastic resin and acidic polysaccharide-based flame retardant (A) used. The temperature during melt mixing corresponds to, for example, the cylinder temperature in a mixing device such as a twin-screw extruder. Furthermore, if multiple temperature settings are available in the cylinder of the mixing device, the cylinder temperature refers to the temperature of the cylinder with the highest temperature. The mixing pressure is not particularly limited, but is preferably 1 to 20 MPa.

[0145] The discharge rate from the mixing device during melt mixing is not particularly limited, but it is preferable to discharge at 10 to 100 kg / hr, and more preferably at 20 to 70 kg / hr, in order to ensure sufficient melt mixing.

[0146] The kneaded mixture, melted and kneaded in the kneading apparatus as described above, is preferably subjected to a cooling treatment after being extruded from the kneading apparatus. The cooling treatment is not particularly limited, and for example, methods such as immersing the mixture in water at 0 to 60°C for water cooling, cooling with gas at -40 to 60°C, or contacting it with metal at -40 to 60°C can be used.

[0147] The flame-retardant resin composition of the present invention can take various forms, such as powder, granules, tablets, pellets, flakes, fibers, and liquid.

[0148] According to the flame-retardant resin composition of the present invention, it is possible to manufacture molded articles that maintain flame retardancy, colorability, and strength, particularly impact strength, while using a naturally derived, environmentally friendly flame retardant, such as an acidic polysaccharide-based flame retardant (A).

[0149] Here, flame retardancy is a type of fire resistance, referring to the property of burning slowly but continuing to burn to a certain extent. There are various standards for evaluating flame resistance, such as JIS and ASTM, but generally, the UL standard is particularly important. The UL standard is a standard established and evaluated by the American company Underwriters Laboratories.

[0150] In a molded article formed from the flame-retardant resin composition of the present invention, when evaluated using a test piece of a predetermined size according to the above UL standards, it is preferable that it be evaluated as passing under UL94HB, more preferably under UL94V-2, and even more preferably under UL94V-0.

[0151] Furthermore, by using the flame-retardant resin composition of the present invention, a molded product can be obtained by the conventional molding method described below, which has sufficient flame retardancy, excellent color matching properties, a good appearance, and excellent mechanical strength such as impact strength.

[0152] Specifically, in a molded article formed from the flame-retardant resin composition of the present invention, the Izod impact strength measured in accordance with JIS K7110 for a test piece of a predetermined size is 4 kJ / m 2 The above is preferable, 7 kJ / m 2 The above is preferable.

[0153] (molded product) Molded articles can be produced using the flame-retardant resin composition of the present invention. These molded articles provide flame-retardant products. When manufacturing the molded articles, the flame-retardant resin composition can be melted and molded in various molding machines. The molding method can be appropriately selected depending on the form and application of the molded article, and examples include injection molding, extrusion molding, compression molding, blow molding, calendering, and inflation molding. Furthermore, sheet-like or film-like molded articles obtained by extrusion molding and calendering can be subjected to secondary molding such as vacuum forming or pressure forming.

[0154] [Flame-retardant resin housing] The present invention provides a flame-retardant resin housing made from a molded article manufactured using the flame-retardant resin composition described above. The articles housed in the flame-retardant resin housing are not particularly limited. Examples of flame-retardant resin housings include housings for various machines and equipment, and other housings generally made from flame-retardant resins.

[0155] (Application) The applications of molded articles including the housing molded from the flame-retardant resin composition of the present invention are not particularly limited, and include, for example, electrical and electronic components, electrical components, exterior parts, and interior parts in fields such as home appliances and automobiles, as well as various packaging materials, household goods, office supplies, piping, and agricultural materials.

[0156] The present invention provides electronic equipment characterized by using the above-mentioned molded product as a component. While not particularly limited, examples of electronic equipment include computers, scanners, copiers, printers, facsimile machines, compositing machines called MFPs (Multi-Function Peripherals) that combine these functions, and digital printing systems for commercial printing. [Examples]

[0157] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples, the units "parts" or "%" are used, and unless otherwise specified, they refer to "parts by mass" or "mass%".

[0158] [Preparation of flame-retardant resin compositions] The following thermoplastic resins and flame retardants (acidic polysaccharide-based flame retardants, phosphorus-based flame retardants, etc.) were prepared as constituent materials for the flame-retardant resin compositions in the examples.

[0159] (thermoplastic resin) As the thermoplastic resin, we prepared ABS resin; Toyorac 700-314 (product name, manufactured by Toray Industries, Inc.).

[0160] (Phosphorus-based flame retardant) As a phosphorus-based flame retardant, we prepared a phosphate ester compound; PX-200 (product name, manufactured by Daihachi Chemical Industry Co., Ltd.).

[0161] (Acid polysaccharide-based flame retardant) As acidic polysaccharide-based flame retardants, acidic polysaccharide-based flame retardants A21-A27, A11, and acidic polysaccharide-based flame retardants Cf1, Cf2 were used, prepared using the acidic polysaccharides shown in Table I and organosilicon compounds or organic compounds that do not contain silicon atoms. Acidic polysaccharide-based flame retardants A21-A27 and A11 are acidic polysaccharide-based flame retardants applicable to the flame-retardant resin composition of the present invention, while acidic polysaccharide-based flame retardants Cf1 and Cf2 are acidic polysaccharide-based flame retardants for comparative examples that are not applicable to the flame-retardant resin composition of the present invention.

[0162] <Preparation of acidic polysaccharide-based flame retardants> The calcium alginate used in the preparation of the acidic polysaccharide-based flame retardant was CAW-80 (product name, M / G ratio: 1.2) manufactured by Kimika Corporation. Table I shows the organosilicon compounds by their product names (all manufactured by Shin-Etsu Chemical Co., Ltd.). The compound names of the organosilicon compounds corresponding to the product names are shown below. In Table I, the abbreviations for solvents are as follows: EtOH for ethanol, Tol for toluene, and MeOH for methanol.

[0163] [Reactive organosilicon compounds] KF-9908; Triethoxysilylethyl polydimethylsiloxyethyl dimethicone KF-9901; Hydrogen dimethicone (functional group equivalent 140 g / mol), kinematic viscosity (25℃): 20 mm 2 / s KBE-3083;n-Octyltriethoxysilane KBM-573; N-phenyl-3-aminopropyltrimethoxysilane [Non-reactive organosilicon compounds] KF-96 50CS; Dimethicone (dimethylpolysiloxane), kinematic viscosity (25℃); 50mm 2 / s

[0164] The acidic polysaccharide-based flame retardant A21 was prepared as follows: Calcium alginate (1 part by mass) was added to stirred ethanol (1.97 parts by mass) and stirred for 10 minutes. The mixture was then immersed in an ultrasonic bath for 30 minutes to apply ultrasonic waves. While stirring, a solution of KF-9908 (0.2 parts by mass) dissolved in toluene (2.17 parts by mass, the same volume as ethanol) was added, and the mixture was stirred for another hour. After removing the solvent under reduced pressure, the resulting powder was heated at 150°C for 1 hour to obtain the reaction product (acidic polysaccharide-based flame retardant A21).

[0165] Similarly, for acidic polysaccharide-based flame retardants A22-A25 and A11, calcium alginate is ultrasonically dispersed with the alcohol (ethanol or methanol) shown in Table I, and then toluene containing a dissolved organosilicon compound is added, followed by the same treatment as described above. For acidic polysaccharide-based flame retardants A26 and A27, the entire amount of solvent is used from the beginning to ultrasonically disperse the calcium alginate, and then the organosilicon compound is added alone, followed by the same treatment as described above. However, the amount of organosilicon compound relative to calcium alginate in acidic polysaccharide-based flame retardants A22-A11 is as shown in Table I.

[0166] As the acidic polysaccharide-based flame retardant Cf1, calcium alginate (CAW-80 manufactured by Kimika Corporation) itself was used.

[0167] The acidic polysaccharide-based flame retardant Cf2 is an example in which sodium laurate, a reactive organic compound that does not contain silicon atoms, is reacted with an acidic polysaccharide instead of a reactive organosilicon compound, and was prepared as follows.

[0168] Specifically, calcium alginate (CAW-80 manufactured by Kimika Co., Ltd.) (1 part by mass) and sodium laurate (0.03 parts by mass) were added to a mixed solvent of ion-exchanged water (3.8 parts by mass) and ethanol (1.6 parts by mass), heated at 95°C for 2 hours, then the solvent was removed by distillation under reduced pressure, repeated centrifugation and washing with water were performed, followed by ethanol washing and filtration, and drying at 100°C for 1 hour to obtain a white powder (acidic polysaccharide-based flame retardant Cf2).

[0169] Here, since calcium alginate has high hygroscopicity, the mass mentioned above is corrected to include the net mass obtained from a test to confirm constant weight after drying at 105°C. Incidentally, the water content of the calcium alginate used in this study was 12.1% by mass. Also, in Table I, for the acidic polysaccharide-based flame retardants A22 to A11, the total amount of solvent is set to 5 ml per gram of solid mass.

[0170] In Table I, the composition of the solvents used in the reaction or mixing is shown as a volume ratio. In the "Silicon-containing" column of Table I, "○" indicates that the organic compound contains silicon atoms, and "×" indicates that the organic compound does not contain silicon atoms.

[0171] [Table 1]

[0172] (Preparation of flame-retardant resin composition) As a pre-drying step before mixing, the thermoplastic resin and flame retardant (acidic polysaccharide-based flame retardant, phosphorus-based flame retardant, etc.) were dried separately at 80°C for 4 hours. Then, they were weighed according to the component ratios (mass%) shown in Table II and dry-blended.

[0173] Next, the mixture obtained by dry blending was supplied at a rate of 10 kg per hour from the raw material supply port (hopper) of a twin-screw extruder (HAAKE twin-screw extruder manufactured by Thermo Scientific). Melt mixing was performed under the conditions of a cylinder temperature of 200°C and a screw rotation speed of 400 rpm. After mixing, the molten resin was cooled in a 30°C water bath and then pelletized in a pelletizer to obtain flame-retardant resin compositions 1 to 13. Flame-retardant resin compositions 1 to 11 correspond to the flame-retardant resin compositions of the present invention, while flame-retardant resin compositions 12 and 13 are comparative examples.

[0174] <Rating> The flame-retardant resin compositions 1 to 13 obtained above were evaluated using the following evaluations 1 to 3. The results, along with the compositions of the flame-retardant resin compositions, are shown in Table II.

[0175] (Rating 1: Toning ability) Each of the obtained pelletized flame-retardant resin compositions 1 to 13 was dried at 80°C for 4 hours, and then molded using an injection molding machine (Rambaldi, Babyplast) with the cylinder temperature set to the temperatures shown in Table II and the mold temperature to 50°C to obtain rectangular test pieces measuring 125 mm in length, 13 mm in width, and 1.6 mm in thickness. The appearance of the obtained test pieces was observed visually, and the colorability was evaluated according to the following criteria. A score of △ or higher was considered acceptable for practical use (passed).

[0176] Here, the cylinder temperature of the injection molding machine was adjusted to the lower end of the temperature range within which fluidity could be ensured for flame-retardant resin compositions 1 to 13. In flame-retardant resin compositions 1 to 11, the fluidity of the flame-retardant resin composition was improved by the reaction or mixing of acidic polysaccharides and organosilicon compounds, making it possible to lower the cylinder temperature to 170°C. On the other hand, in flame-retardant resin compositions 12 and 13, a cylinder temperature of 180°C was necessary to ensure fluidity.

[0177] ◎: Close to white, and allows for a very wide range of coloring options. ○: It is cream-colored and can be colored in a wide range of ways. △: It is light brown and may be usable for dark colors other than black. ×: It is dark brown and difficult to use for anything other than black.

[0178] (Rating 2: Flame retardant) The test specimens obtained above were conditioned for 48 hours in a constant temperature chamber at 23°C and 50% humidity, and then subjected to flame retardancy testing in accordance with the UL94 test (combustion test for plastic materials for equipment components) established by Underwriters Laboratories (UL) in the United States. The UL94V test method was adopted, and flame retardancy was evaluated based on the following evaluation criteria.

[0179] ◎:V-0 (passed) ○:V-1 (passed) △:V-2 (passed) ×: Not conforming to specifications (does not meet V-2 standards = fails)

[0180] (Rating 3: Impact strength) Each of the obtained pelletized flame-retardant resin compositions 1 to 13 was dried at 80°C for 4 hours, and then molded using an injection molding machine (Rambaldi, Babyplast) with the cylinder temperature set to the temperatures shown in Table II and the mold temperature to 50°C to obtain test specimens measuring 80 mm in length, 10 mm in width, and 4.0 mm in height.

[0181] The molding process involved discarding 10 shots, followed by 10 consecutive shots. The Izod impact strength of the 10 resulting molded parts was measured using a method compliant with JIS K7110 and evaluated according to the following criteria. An impact strength of ○ or higher was considered acceptable for practical use (passed).

[0182] ◎: 7kJ / m 2 That's all. ○: 4kJ / m 2 More than 7kJ / m 2 less than ×: 4kJ / m 2 less than

[0183] [Table 2]

[0184] Table II shows that the flame-retardant resin compositions of the present invention result in molded articles with reduced environmental impact and excellent flame retardancy, colorability, and impact strength. Furthermore, in the case of flame-retardant resin compositions 1 to 11, the colorability, flame retardancy, and impact strength of molded articles molded at a cylinder temperature of 180°C were at a level that was practically acceptable (passable).

Claims

1. A flame-retardant resin composition containing a thermoplastic resin and a flame retardant, The flame retardant comprises one or more acidic polysaccharides selected from polysaccharides having acidic functional groups, derivatives of polysaccharides having acidic functional groups modified while retaining at least a portion of the acidic functional groups, and salts thereof, and a mixture of an acidic polysaccharide and a non-reactive organosilicon compound, a reaction product of a reactive organosilicon compound that is reactive with the acidic polysaccharide and the acidic polysaccharide, or both the mixture and the reaction product. The aforementioned acidic polysaccharide contains calcium alginate, The non-reactive organosilicon compound does not have a functional group that is reactive with the acidic polysaccharide. The ratio of the non-reactive organosilicon compound to the acidic polysaccharide in the mixture is within the range of 2 to 30% by mass. The ratio of the reactive organosilicon compound to the acidic polysaccharide in the reaction product is within the range of 2 to 30% by mass. The mixture and the reaction product are acidic polysaccharide-based flame retardants. A flame-retardant resin composition characterized in that the content of the acidic polysaccharide-based flame retardant is within the range of 5 to 40% by mass relative to the total amount of the flame-retardant resin composition.

2. The flame-retardant resin composition according to claim 1, characterized in that the flame-retardant resin composition contains the reactant, and the reactive organosilicon compound contains a reactive silicone oil or a silane coupling agent.

3. The flame-retardant resin composition according to claim 1 or 2, characterized in that the ratio of the non-reactive organosilicon compound to the acidic polysaccharide in the mixture and the ratio of the reactive organosilicon compound to the acidic polysaccharide in the reactant are each within the range of 2 to 30% by mass.

4. Furthermore, the flame-retardant resin composition according to any one of claims 1 to 3 is characterized by containing a phosphorus-based flame retardant in an amount of 1 to 20% by mass relative to the total amount of the flame-retardant resin composition.

5. A flame-retardant resin housing made using a flame-retardant resin composition, A flame-retardant resin housing characterized in that the flame-retardant resin composition is the flame-retardant resin composition described in any one of claims 1 to 4.

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