JP2003147087A - Flame retardant resin and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame retardant resin excellent in flame retardance without spoiling inherent characteristics of the resin, processability in molding and generating no harmful gases during combustion. SOLUTION: A tin compound is reacted with a high polymer obtained by homopolymerization of a monomer having at least one species of acidic groups selected from sulfo, carboxy, phenolic hydroxy,-OPO(OH)2 and -PO(OH)2 or copolymerization of the monomer with another monomer or a polymer introduced with an acidic group to form ion pairs between the acidic groups and the tin salt compound. Thus, the tin salt in the resin presents in a state of ion pairs with the acidic groups in the polymer chain and expresses flame retardance owing to homogeneous dispersion of the ion pairs in a molecular level in more active state in the polymer chains.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant resin obtained by treating a polymer compound having an acidic group with a tin salt compound to make it flame-retardant, and a method for producing the flame-retardant resin.

[0002]

2. Description of the Related Art In recent years, plastics have come to be used in a wide range of application fields along with the improvement of their performances, and have become indispensable in our lives.
However, in spite of its excellent characteristics, the drawback of easy burning is becoming a big problem. For this reason, from the viewpoint of safety, it has become more important to make plastics flame-retardant on a global level. Furthermore, recently, from the viewpoint of global environment protection, not only is it difficult to burn, but generation of harmful gas and smoke during combustion, corrosiveness, etc. have been taken into consideration.

As a method of making a plastic material flame-retardant,
It is common to add a flame retardant to the plastic, and as the flame retardant, there are three types, that is, a halogen flame retardant, an inorganic flame retardant, and a phosphorus (phosphate ester) flame retardant.

[0004]

However, these flame retardants have the following problems.

Halogen-based flame retardant When burned, a substance harmful to the human body such as dioxins and an acidic gas such as hydrogen chloride that corrodes an incinerator are generated.
From the viewpoint of global environment conservation, it is likely that the use will be restricted or prohibited in the future.

Inorganic flame retardant has a low flame retardant effect, and therefore, the amount of flame retardant added is not less than 10%.
Since it is necessary to add several tens of%, the characteristics originally possessed by plastics are impaired and the processing during molding becomes difficult. For example, plastics such as tensile elongation and impact strength are reduced, and the weight is increased. Further, the flowability of the plastic at the time of molding is deteriorated, and the molding accuracy and the molding processing capacity are lowered, so that the fine workability and the production efficiency are deteriorated.

Phosphorus-based (phosphate ester-based) flame retardant has a plasticizing effect on plastics and greatly reduces heat resistance. Specifically, the deflection temperature under load is 10
It also drops by ~ 30 ° C. In addition, the flame retardant volatilizes and adheres to the mold during molding of the plastic, making uniform and stable molding difficult.

Among the above flame retardants, since they do not contain a halogen component, they are less added to the environment, and
Phosphorus-based (phosphate ester-based) flame retardants, which have a higher flame-retardant effect than inorganic-based flame retardants and require only a small amount to be added, are considered to be the most promising, and the amount used is increasing year by year.

However, as described above, the phosphorus-based (phosphate ester-based) flame retardant also has various problems, so that it is possible to obtain a flame-retardant plastic (resin) having sufficiently satisfactory characteristics. The current situation is that it is not possible.

Therefore, the present invention provides a flame-retardant resin which is excellent in flame retardancy, does not deteriorate the original characteristics of the resin and the processability during molding, and does not generate harmful gas during combustion. The purpose is to Moreover, it aims at providing the manufacturing method of such a flame-retardant resin.

[0011]

The flame-retardant resin according to the present invention is at least one selected from a sulfone group, a carboxyl group, a phenolic hydroxyl group, -OPO (OH) ₂ group and -PO (OH) ₂ group. In the polymer compound obtained by homopolymerization of the monomer having an acidic group or copolymerization of the monomer with another monomer or the polymer compound into which the acidic group is introduced, the tin salt compound and a counter ion It is a flame-retardant resin formed.

When the tin salt is introduced into the resin, it exists in the state of counter ions with the acidic groups in the polymer chain, and is evenly scattered in the polymer chain at the molecular level in a more active state. Becomes As a result, at the time of combustion, the radical gas generated by the oxidation reaction can be efficiently trapped, and as a result, flame retardancy is achieved.
It should be noted that even if compared with other metal salts, the use of tin salt provides particularly excellent flame retardancy.

The flame-retardant resin as described above may be used as a resin molded product as it is, but may be mixed with another resin and used as a flame retardant. When such a flame retardant resin is contained as a flame retardant, the heat resistance and flame retardancy of this resin composition can be improved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of the flame-retardant resin according to the present invention will be described below.

Embodiment The flame-retardant resin according to the present embodiment has an acidic group, and the acidic group is treated with a tin salt compound.

To produce this flame-retardant resin, a tin salt compound may be reacted with a polymer compound having an acidic group.

First, examples of the acidic group contained in the resin include a sulfone group, a carboxyl group, a phenolic hydroxyl group, -OPO (OH) ₂ group and -PO (OH) ₂ group. Of these, a sulfone group, a carboxyl group, and a phenolic hydroxyl group are preferable. When a molded product is obtained with this resin as a main component, if the introduction rate of the acidic group to the resin is too small, the effect of improving flame retardancy and heat resistance is small, and if it is too large, the characteristics of the resin itself are impaired. Therefore, the introduction rate of the acidic group is preferably 1 to 50 mol%. Further, when this resin is added to other resins as a flame retardant, if the introduction rate of acidic groups to the resin is too low, the effect as a flame retardant becomes insufficient, and if it is too high, it is Since the compatibility is deteriorated and the water absorption is increased, the introduction rate of the acidic group is preferably 5 to 95 mol%.

As the resin having such an acidic group,
Examples thereof include those obtained by modifying the polymer, and those obtained by homopolymerizing a monomer having an acidic group or copolymerizing with a monomer.

When the polymer is modified, the polymer can be classified into those having an aromatic ring or a heterocycle in the main chain and side chains and those not containing the aromatic ring or the heterocycle. The former are polystyrene and polyphenyl. Ether, polyphenylene sulfide, ABS (acrylonitrile-butadiene-styrene) resin, ASA (acrylic-styrene-acrylonitrile) resin, SB (butadiene-styrene)
Resin, SAN (styrene-acrylonitrile) resin, phenol resin, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polysulfone, polyallyl sulfone, polyether sulfone, polythioether sulfone, polyether ketone, polyetherimide, polyether ether ketone, polyamide , Polyamideimide, polyimide, polyarylate,
Aromatic polyesters, epoxy resins, polyurethanes, polyvinyl chloride, chlorinated polyethers, polychloromethylstyrene and the like can be mentioned, and the latter can be cellulose, polyvinyl alcohol, chitin and the like. Note that these polymers may be unused virgin materials or used waste materials.

As a method for introducing an acidic group into these polymers, it is sufficient to react the polymers with an oxidizing agent,
When forming a sulfone group as an acidic group, sulfuric acid, chlorosulfonic acid, fuming sulfuric acid, concentrated sulfuric acid or the like may be used as an oxidizing agent, and when forming a carboxyl group as an acidic group, as an oxidizing agent, Carbon dioxide, dry ice, various α-halogen-substituted carboxylic acids, etc. may be used, and as acidic groups, —OPO (OH) ₂ , —PO (OH)
_{When 2} is formed, phosphoric acid, phosphoric acid ester, phosphorus pentoxide, phosphorus trioxide or the like may be used as the oxidizing agent.

For example, in order to introduce a sulfo group into polystyrene, a sulfonated polystyrene can be obtained by reacting with concentrated sulfuric acid, and to introduce a carboxyl group into cellulose, it can be converted into cellulose acetate by reacting with acetic acid. Good. Further, by adding n-butyllithium to a polymer having an aromatic ring and further reacting it with dry ice, a carboxylic acid-containing polymer can be obtained, and a polymer having a hydroxyl group such as polyvinyl alcohol is reacted with phosphorus pentoxide. If you do, -OPO (OH)
A polymer with ₂ groups can be obtained. The range in which the acidic group is introduced may be the entire target resin or only the resin surface.

When a monomer having an acidic group is homopolymerized or copolymerized with another monomer to obtain a resin having an acidic group, examples of the monomer having an acidic group include acrylic acid, methacrylic acid, vinylbenzenesulfonic acid, Vinylbenzyl sulfonic acid, vinyl sulfonic acid, vinyl benzoic acid, vinyl benzyl carboxylic acid, vinyl phenol,
Mono (2-acryloyloxyethyl) acid phosphate, mono (2-methacryloyloxyethyl) acid phosphate, 2-methacryloyloxyethyl acid phosphate, vinyl benzene phosphate, vinyl benzyl phosphate, vinyl phosphate, phenol (however, Addition polymerization) and the like.
Further, as the monomer to be copolymerized with the monomer having such an acidic group, styrene, α-methylstyrene,
Alkyl styrene, ethylene, propylene, acrylic acid ester, methacrylic acid ester, butadiene, acrylonitrile, acrylamide, alkyl vinyl ketone,
Vinyl acetate, vinylpirudin, N-vinylpyrrolidone,
Tetrafluoroethylene, vinyl chloride, vinylidene chloride, N-
Examples thereof include vinylcarbazole, maleic anhydride, vinylnaphthalene, formaldehyde (against phenol). As a method for polymerizing these monomers, radical polymerization is generally used, but ionic polymerization may be used. In addition,
Similarly for condensation polymerization and polyaddition type polymers, a resin having an acidic group can be obtained by homopolymerization of a monomer having an acidic group or copolymerization with another monomer.

The resin having an acidic group obtained as described above may be used alone or as a blend or alloy with another polymer having an acidic group or a polymer having no acidic group. Good. Polymers having no acidic groups to be blended include nylon resins, polyolefin resins such as polyethylene and polypropylene, polystyrene, polyphenylene ether, polyphenylene sulfide, ABS resin, ASA resin, S
B resin, SAN resin, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polysulfone, polyallyl sulfone, polyether sulfone,
Polythioether sulfone, polyether ketone, polyetherimide, polyetheretherketone, polyamide, polyamideimide, polyimide, polyarylate, aromatic polyester, epoxy resin, polyurethane, polyvinyl chloride, chlorinated polyether, polychloromethylstyrene, Cellulose, polyvinyl alcohol,
Examples include chitin, polyacrylic acid ester, and polymethacrylic acid ester. In addition to the above-mentioned blending polymers, glass fibers, carbon black, calcium carbonate, bengal, talc, silica, and other general resin additives such as colorants, plasticizers, antioxidants, and antistatic agents. Alternatively, other flame retardants may be added.

The flame-retardant resin according to the present embodiment can be obtained by reacting a resin having such an acidic group with a tin salt compound. Examples thereof include oxides, hydroxides, halides, alcoholates, and compounds with various acids. Specifically, stannous sulfate, stannous oxide, stannic oxide, stannous chloride, stannic chloride, Sn (OR) ₄ (R
= Tin alcoholate represented by C 1-8 aliphatic hydrocarbon), tin acetate, tin fluoride, tin borofluoride,
Tin diphosphate, 2-ethylhexanetin, phthalocyanines, tin trifluoromethanesulfonate, tin iodide, tin oxalate, tin tetrabromide, potassium stannate, sodium stannate, stannous pyrophosphate, metastannic acid Etc. can be used, among them, among others, stannous sulfate, stannous oxide, stannic oxide, tin alcoholate, tin acetate, tin diphosphate,
It is preferable to use tin oxalate, phthalocyanines, stannous chloride, stannic chloride, or tin iodide.

In order to react such a tin salt compound with a resin having an acidic group, the resin having an acidic group is dissolved or immersed in an organic solvent or water, and the tin salt compound is used as it is or in an organic solvent or water. What is dissolved may be added. Further, the resin having an acidic group may be melted by heating. After the reaction, the flame-retardant resin may be taken out by removing the solvent from the system.

If the flame-retardant resin thus obtained is thermoplastic, it can be formed into a desired product shape by molding or press molding. On the other hand, in the case of thermosetting, a resin molded article having a desired shape may be immersed in a solution in which a tin salt compound is dissolved to make the surface flame-retardant. Alternatively, it may be reacted in advance with a tin salt compound in a monomer state and then polymerized.

As described above, when the tin salt is introduced into the resin, it is present in the state of counterions with the acidic groups in the polymer chain, and in a more active state, it is homogeneous in the polymer chain at the molecular level. Will be scattered around. As a result, at the time of combustion, the radical gas generated by the oxidation reaction can be efficiently trapped, and as a result, flame retardancy is achieved.

The flame-retardant resin according to this embodiment is
Although it may be used as a resin molded product as it is, it may be mixed with another resin and used as a flame retardant. When such a flame retardant resin is contained as a flame retardant, the heat resistance and flame retardancy of this resin composition can be improved.

[0029]

EXAMPLE A flame-retardant resin was actually produced and the flame-retardant property was evaluated.

<Experiment> A flame-retardant resin having an acidic group and treated with a tin salt compound is evaluated.

Example 1 In this example, sulfonated polyphenylene ether (SPPE) was treated with stannic sulfate as a flame-retardant resin having an acidic group and treated with a tin salt compound. What was done was produced.

Specifically, 2,6-dimethylphenylene ether (manufactured by Aldrich, weight average molecular weight Mw = about 35,000) is prepared as PPE, and 1,2-dichloroethane is first added to 2,6- Dimethylphenylene ether (manufactured by Aldrich, weight average molecular weight Mw = about 3.5)
10,000) was dissolved, a mixed solution of concentrated sulfuric acid and acetic anhydride (molar ratio 1: 1.2) was added thereto, and a heating reaction was carried out at 60 ° C. for 5 hours. After completion of the reaction, the mixture was poured into hot water, washed and reprecipitated, and the obtained precipitate was dried to obtain 9.1 mol% of SPPE. The sulfonation rate was adjusted by the amount of concentrated sulfuric acid charged.

Then, this SPPE was dissolved in tetrahydrofuran, and stannic sulfate dissolved in water was added thereto.
An equimolar amount was added to the sulfone group. Then, the solvent was removed and the resin was dried to obtain a resin containing a tin salt. This is the sample resin of Example 1.

Example 2 In this example , sulfonated high-impact polystyrene (hereinafter referred to as SHIPS) is used as a flame retardant resin having an acidic group and treated with a tin salt compound. The thing processed with tin was produced.

Specifically, high-impact polystyrene (crushed product of used VHS cassette housing material)
(Hereinafter referred to as HIPS) was prepared and sulfonated in the same manner as in Example 1 to obtain SHIPS in which 30 mol% was sulfonated.

The SHIP thus obtained
S was dissolved in tetrahydrofuran, and stannic chloride dissolved in water was added thereto in an equimolar amount with respect to the sulfone group. Then, the solvent was removed and the resin was dried to obtain a resin containing a tin salt. This is a sample resin of Example 2.

Example 3 Here, ethylene-methacrylic acid copolymer (EMAA) was treated with stannic oxide as a flame-retardant resin having an acidic group and treated with a tin salt compound. The thing was produced.

Specifically, EMAA containing 10% by weight of carboxylic acid (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: Nucrel N035) is prepared, and this EMAA is heated and melted. , Stannic oxide was added in an equimolar amount to the methacrylic acid unit.
Then, by extrusion, a resin containing tin salt in pellet form was obtained. This is designated as the sample resin of Example 3.

Example 4 Here, as a flame-retardant resin having an acidic group and treated with a tin salt compound, carboxylated polystyrene (hereinafter referred to as CPS) and sulfonated polyphenylene ether ( A mixture with SPPE) treated with tetraethoxytin was prepared.

Specifically, first, styrene monomer, 4
-Vinylbenzoic acid and a polymerization initiator (benzoyl peroxide) were dissolved in tetrahydrofuran and radical-copolymerized at 50 ° C under a nitrogen stream. After completion of the polymerization, reprecipitation with a large amount of methanol and drying the obtained precipitate,
5.2 mol% CPS was obtained. The content of carboxylic acid was adjusted by the charged amount of the monomer. In addition, as the PPE, 2,6-dimethylphenylene ether (manufactured by Aldrich, weight average molecular weight Mw = about 35,000) is prepared,
This was sulfonated as described in Example 1. Then, a mixture of CPS and SPPE mixed at a weight ratio of 60:40 was dissolved in tetrahydrofuran, and tetraethoxytin powder was added thereto in an equimolar amount with respect to the total of sulfone groups and carboxyl groups. did. Then, the solvent was removed and the resin was dried to obtain a resin containing a tin salt. This is designated as the sample resin of Example 4.

Example 5 In this example , a mixture of polystyrene (PS) and sulfonated polyphenylene ether (SPPE) treated with tin acetate was prepared.

Specifically, first, PS (weight average molecular weight Mw = about 280,000) and SPPE produced in the same manner as in Example 1 were mixed in a weight ratio of 20:80. It was dissolved in tetrahydrofuran, and tin acetate dissolved in water was added thereto in an equimolar amount with respect to the sulfone group. Then, the solvent was removed and the resin was dried to obtain a resin containing a tin salt. This is designated as the sample resin of Example 5.

Example 6 In this example, a resin obtained by treating SHIPS with stannic chloride was used as a flame retardant, and polyphenylene ether (PP
E).

Specifically, first, SHIPS produced in the same manner as in Example 2 was treated with stannic chloride as a flame retardant, which was used in a weight ratio of 20:80 with PPE.
To obtain pellets by extrusion. This is designated as a sample resin of Example 6.

Comparative Example 1 For comparison, the same PPE as that used in Example 1 was used.
Is prepared as a sample resin of Comparative Example 1.

Comparative Example 2 Here, the same HIPS as that used in Example 2 was prepared. This is designated as a sample resin of Comparative Example 2.

Comparative Example 3 Here, the same EMAA as that used in Example 3 was prepared. This is used as a sample resin of Comparative Example 3.

Comparative Example 4 Here, a mixture of PS and PPE was prepared in a weight ratio of 60:40. This is designated as a sample resin of Comparative Example 4.

Comparative Example 5 Here, a mixture was prepared in which PS and PPE were mixed at a weight ratio of 20:80. This is used as a sample resin of Comparative Example 5.

Comparative Example 6 In this example, the same SPPE as in Example 1 was treated with sodium chloride to prepare it. This is used as a sample resin of Comparative Example 6.

Comparative Example 7 In this example, the same CPS used in Example 4 was treated with sodium chloride to prepare it. Comparative Example 7
Sample resin.

Evaluation of Properties Heat resistance and flame retardancy were evaluated for each sample resin as described above. Specifically, each sample resin as described above is heated at 260 ° C. and 9.8 Pa with a high temperature press.
After being molded into a plate having a thickness of 1.0 mm under the above conditions, a differential scanning calorimeter (manufactured by Perkin Elmer Co., Ltd., trade name: DSC
-7), heat resistance was evaluated by measuring the glass transition temperature Tg at a temperature rising rate of 20 ° C./min, and UL was measured.
Subject 94 V method and UL Subject
Flame retardancy was evaluated by the 94 HB method. The results are shown in Table 1.
Is shown together with the contents of each sample resin.

The flame-retardant grade is V-0> V-
1>V-2> HB.

[0054]

[Table 1]

From Table 1, Example 1, Comparative Example 1, and Example 2
And Comparative Example 2, Example 3 and Comparative Example 3, Example 4 and Comparative Example 4
Comparing with, it can be seen that heat resistance and flame retardancy are improved by introducing an acidic group into the resin and treating with a tin salt compound. Also, comparing Example 5 with Comparative Example 5,
It can be seen that even if a mixture of a resin having an acidic group and a resin having no acidic group is treated with a tin salt compound, the flame retardancy can be improved. In addition, as in Comparative Examples 6 and 7, even if an acidic group is introduced into a resin and treated with a sodium salt, flame retardancy is not improved. Therefore, it is effective to use tin as compared with other metals. It can be seen that it is.

Further, comparing Example 6 with Comparative Example 5,
It can be seen that the flame-retardant resin having an acidic group and treated with a phosphoric acid compound exerts a sufficient effect even when blended with another resin and used as a flame retardant.

[0057]

As is apparent from the above description, when the present invention is applied to react a polymer compound having an acidic group with a tin salt compound, the flame retardancy of the resin obtained by this reaction is increased. Can be significantly improved. Further, even if this resin is mixed with another resin and used as a flame retardant, the flame retardancy can be significantly improved.

Further, when the present invention is applied, adhesion to a mold or a mold with a volatile gas is not deteriorated as in the case of adding a conventional flame retardant without deteriorating the original characteristics of the resin such as heat resistance. No problems such as corrosion will occur during molding. Further, unlike the case where the halogen-containing flame retardant is added, no harmful gas is generated at the time of combustion, so that adverse effects on the global environment can be suppressed.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J031 BA22 BA28 BA29 BC19 BD24                       BD30 CD03 CD25 CD27 CD28                 4J100 AB02P AB07P AC03P AD02P                       AJ02P AK32P AL08P AP01P                       AP07P BA01H BA03P BA16P                       BA17H BA56H BA56P BA64H                       BA65P HA01 HA31 HB29                       HB36 HB39 HB52 HB63 HC12                       HC27 HC85 HC88 HD01 HE05                       HE12 HE14 JA43 JA44

Claims (4)

[Claims] 1. A homopolymerization of a monomer having at least one acidic group selected from a sulfone group, a carboxyl group, a phenolic hydroxyl group, a —OPO (OH) ₂ group, and a —PO (OH) ₂ group, or the monomer and other monomers. A flame-retardant resin obtained by forming a counter ion with a tin salt compound by the above-mentioned acidic group in the polymer compound obtained by copolymerization with the above-mentioned monomer or the polymer compound into which the above-mentioned acidic group is introduced. 2. The flame-retardant resin according to claim 1, wherein the polymer compound having an acidic group has an aromatic ring or a heterocycle in a main chain and / or a side chain. 3. A homopolymerization of a monomer having at least one acidic group selected from a sulfone group, a carboxyl group, a phenolic hydroxyl group, a —OPO (OH) ₂ group, and a —PO (OH) ₂ group, or the monomer and other monomers. The tin salt compound acts on the polymer compound obtained by copolymerization with the monomer or the polymer compound into which the above acidic group has been introduced to form a counter ion between the above acidic group and the above tin salt compound. A method for producing a flame-retardant resin, which comprises: 4. The method for producing a flame-retardant resin according to claim 3, wherein the polymer compound having an acidic group has an aromatic ring or a heterocycle in a main chain and / or a side chain.