JPH1135675A - Reversibly thermally cleavable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermally cleavable resin having a crosslinked structure and high physical properties at the ordinary temperature but capable of being thermally cleaved to produce a resin low in melting viscosity and excellent in moldability by subjecting an alkenyl ether group-containing compound and a carboxyl group-containing compound to an addition reaction in the presence of a specific catalyst. SOLUTION: This reversibly thermally cleavable resin composition is obtained by subjecting (A) a compound containing (m) alkenyl ether groups and (B) a compound containing (n) carboxyl groups to an addition reaction in the presence of a catalyst comprising a phenolic compound (preferably nitrophenol, etc.), or a hydroxyamine (preferably ethanolamine, etc.), [(m), (n) are each >=2, wherein at least one of (m), (n) is 3 or larger]. The component A includes triethylene glycol dipropenyl ether and a copolymer of a propenyl ether- containing acrylic monomer with styrene monomer. The component B includes dodecanedicarboxylic acid and acrylic acid copolymers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a reversible heat-cleavable resin. More specifically, the present invention relates to a thermally cleavable resin composition having a low melt viscosity and excellent moldability since a chemical bond of the crosslinked structure is cleaved by heating, despite having high physical properties due to having a crosslinked structure at normal temperature.

[0002]

2. Description of the Related Art Conventional thermoplastic resins such as polypropylene, polyethylene and polystyrene do not have a crosslinked structure and are often insufficient in physical properties. When a crosslinked structure is introduced into these thermoplastic resins, the physical properties are improved, but the thermoforming temperature is increased, so that thermoforming becomes difficult. As a thermoplastic resin having a crosslinked structure, an ionomer resin is conventionally known. However, this resin has a high thermoforming temperature, and at present, there is no satisfactory thermoplastic resin having a crosslinked structure.

[0003]

The problem to be solved by the present invention is that, while having a high physical property having a crosslinked structure, a specific chemical bond of the crosslinked structure is cleaved by heating and the melt viscosity is low. The object of the present invention is to provide an excellent thermoplastic resin.

[0004]

The present inventors have conducted intensive studies on chemical bonds which cause reversible addition and cleavage reactions and catalysts suitable therefor. As a result, a resin having high physical properties and good moldability has been obtained. The present inventors have found a thermoplastic resin having a crosslinked structure and a specific catalyst capable of reversibly controlling an addition reaction and a cleavage reaction, and reached the present invention.

That is, the first invention relates to a compound (A) containing m alkenyl ether groups in the molecule and a compound (B) containing n carboxyl groups in the molecule, and a phenolic compound (C1 ) Or a thermally cleavable resin (I) obtained by performing an addition reaction in the presence of a catalyst of a hydroxyamine compound (C2) (where m and n are integers of 2 or more, and at least one of m or n is 3) Or an integer greater than or equal to).

The second invention relates to a resin (D) having a divalent chemical bond represented by the following general formula (1) in a molecular chain:
And a thermally cleavable resin composition (II) comprising a catalyst of a phenolic compound (C1) or a hydroxyamine compound (C2). (Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² and R ³ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms)

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The compound (A) containing an alkenyl ether group in the first invention of the present invention may be a low molecular compound, a high molecular compound or a prepolymer. Further, the alkenyl ether group is a terminal of the compound,
It may be in the molecular chain or in the side chain of the molecule. The alkenyl ether group of the present invention is an alkenyl ether group having usually 2 to 6 carbon atoms, and specific examples thereof include a propenyl ether group, a vinyl ether group, and an isopropenyl ether group. Preferred are a propenyl ether group and a vinyl ether group. Group. Further, compound (A)
Is a heterocyclic ring containing a hydrocarbon group, ether group, thioether group, carbonyl group, ester group, imino group, amide group, urethane group, urea group, carbonate group, siloxy group, nitrogen atom or oxygen atom in its molecular chain. It may contain an organic group (a) such as a structural group.

As a specific example of the compound (A), in the case of a low molecular weight compound, for example, a compound containing a propenyl ether group such as triethylene glycol dipropenyl ether or ethylene glycol dipropenyl ether; a compound containing a vinyl ether group such as triethylene glycol divinyl ether And the like. In the case of a high molecular compound, for example, a copolymer of an acrylic monomer containing a propenyl ether group and a styrene monomer; an acrylic copolymer of a monomer containing a vinyl ether group and an acrylic monomer are exemplified.

Further, the compound (A) containing a carboxyl group in the first invention of the present invention may be a low molecular compound, a high molecular compound or a prepolymer. In addition, the carboxyl group may be located at the terminal of the compound, in the molecular chain, or in the side chain of the molecule. Further, the compound (B) may contain the same organic group (b) as the above-described organic group (a) in the molecular chain.

As specific examples of the compound (B), in the case of a low molecular weight compound, for example, a polyfatty acid such as dodecanedioic acid and an aromatic polycarboxylic acid such as terephthalic acid can be mentioned. In the case of a polymer compound, for example, an acrylic acid copolymer;
Styrene copolymer containing a carboxyl group; carboxyl group terminal or side chain polyester, polyamide, polyurethane and the like.

In the present invention, the values of m and n are 2
In the above integer, at least one of m and n is an integer of 3 or more.

The catalyst (C) which can control the reversibility of the addition reaction and the cleavage reaction in the present invention includes a phenol compound (C1) and a hydroxyamine compound (C
2).

In the present invention, the phenolic compound (C)
1) includes phenol, nitrophenol, dinitrophenol, trinitrophenol, bromophenol, fluorophenol, chlorophenol, iodophenol, aminophenol, monoalkylphenol, dialkylphenol, trialkylphenol,
Monohydric phenols such as tetraalkylphenol and pentaalkylphenol; polyhydric phenols such as catechol, resorcinol, hydroquinone and pyrogallol; naphthol; and the like, among which nitrophenol, phenol and chlorophenol are preferable.

Further, a hydroxyamine compound (C2)
Examples thereof include alkanolamines such as monoalkanolamine, dialkanolamine and trialkanolamine, and among these, preferred are triethanolamine, diethanolamine and ethanolamine.

The amount of the catalyst used is not particularly limited, but is usually 1 to 50 mol%, preferably 30 to 40 mol%, based on the alkenyl ether group.

In the method for producing the thermally cleavable resin of the present invention, the compounds (A) and (B) and the catalyst (C) are mixed and heated to perform an addition reaction between an alkenyl ether group and a carboxyl group. When (A) or (B) is a solid, it may be used as a mixture in a powder state, or may be used after being dissolved in an organic solvent.

The temperature of the addition reaction between the alkenyl ether group and the carboxyl group in the thermally cleavable resin (I) of the present invention varies depending on the type of the catalyst (C).
40 ° C. For example, when nitrophenol is used as a catalyst, the addition reaction is completed at 100 ° C. within one hour.

The temperature of the thermal cleavage reaction of the chemical bond represented by the following general formula (1) in the thermoplastic resin (I) of the present invention varies depending on the type of catalyst, but is usually from 130 ° C. to 160 ° C.
It is. For example, when nitrophenol is used as a catalyst, the thermal cleavage reaction is completed at 130 ° C. within one hour.

The second aspect of the present invention relates to a resin (D) having a divalent chemical bond represented by the following general formula (1) in a molecular chain and a phenolic compound (C1) or a hydroxyamine-based compound. A thermally cleavable resin composition (II) comprising a catalyst of the compound (C2). (In the formula, R ¹ represents a hydrogen atom or a methyl group; R ² and R ³ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

The type of the resin (D) having a chemical bond in the thermally cleavable resin composition (II) of the present invention is not particularly limited, but the alkenyl ether group in the molecule described in the description of the first invention is used. Is a resin obtained by an addition reaction between a compound (A) containing a compound (B) and a compound (B) containing a carboxyl group in the molecule, and the compounds (A) and (B) may be low-molecular compounds or high-molecular compounds Alternatively, it may be a prepolymer. The type of the polymer compound (A) or (B) is
Acrylic resin, polystyrene resin, polyolefin resin, polyurethane resin, polyester resin, polyamide resin, polyether resin, polysiloxane resin, polycarbonate resin and the like can be used, preferably acrylic resin, Polystyrene resin,
Polyolefin resin, polyurethane resin, polyester resin, and polyamide resin. As a method of introducing an alkenyl ether group into the skeleton of the resin, for example, by copolymerizing an acrylic monomer containing an alkenyl ether group with a copolymerizable vinyl monomer, an acrylic resin, a polystyrene resin, a polyolefin resin Is obtained. In addition, as a method of introducing a carboxyl group into the resin skeleton, an acrylic resin, a polystyrene resin, or a polyolefin resin can be obtained by copolymerizing an acrylic acid monomer with a copolymerizable vinyl monomer. And a method of obtaining a polyester resin or a polyamide resin with an excess of polycarboxylic acid, and a method of obtaining a polyurethane resin from a polyol having a carboxyl group and polyisocyanate.

As the catalyst used for the thermal cleavage reaction, the same phenol compound (C1) and hydroxyamine compound (C2) as those used in the first invention can be used.

The temperature of the cleavage reaction of the thermally cleavable resin (II) of the present invention varies depending on the type of catalyst, but is usually from 130 ° C. to 1 ° C.
60 ° C. For example, when a nitrophenol catalyst is used, the cleavage reaction is completed at 130 ° C. within one hour.

The heat-cleavable resin (I) of the first invention and the heat-cleavable resin (II) of the second invention have a catalyst of a phenol compound (C1) and a hydroxyamine compound (C2). Therefore, the chemical bond represented by the above general formula (1) is cleaved by heating, and unlike a polymer having a crosslinked structure at room temperature, the molecular weight is reduced, and the melt viscosity of the resin is significantly reduced. There are features. Therefore, casting,
Excellent moldability during molding processes such as extrusion molding, compression molding, transfer molding, injection molding, and suction molding.

The chemical bond represented by the above general formula (1) can be cleaved by using another catalyst such as 2-ethylhexyl phosphoric acid, but the dissociated propenyl ether group immediately undergoes self-polymerization. There is a drawback that it will cause it. On the other hand, when the phenolic compound (C1) or the hydroxyamine compound (C2) used in the present invention is used as a catalyst, there is no such adverse effect, and a stable resin composition can be reversibly reduced in melting. Viscosity can be realized.

[0025]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. In the following:
"Parts" represents parts by weight.

<Production of Resin> Example 1 First, 100 parts of 2-hydroxyethyl methacrylate,
Glycidylpropenyl 100 parts, triethylamine 10
And phenothiazine as a polymerization inhibitor were reacted at 100 ° C. for 5 hours, and purified by distillation to obtain a propenyl ether group-containing acrylate monomer. Next, 52 parts of this propenyl ether group-containing acrylate monomer and 48 parts of styrene monomer were used as polymerization initiators, and 3 parts of azoisobutyronitrile (AIBN) and 0.1 part of dodecanethiol were dissolved in 100 parts of xylene. The polymerization reaction was carried out for 4 hours to obtain a xylene solution of a propenyl ether group-containing styrene copolymer (number average molecular weight 5000, number of propenyl ether groups 15 in the molecule). To this propenyl ether group-containing styrene copolymer solution, 10 parts of dodecanediacid and 4 parts of nitrophenol were added, and subjected to an addition reaction at 100 ° C., followed by drying under reduced pressure to obtain a heat-cleavable resin of the present invention.

Comparative Example 1 First, 100 parts of 2-hydroxyethyl methacrylate,
100 parts of sodium methylate and 5 parts of phenothiazine as a polymerization inhibitor were subjected to methanol removal at 80 ° C. under reduced pressure. Add 100 parts of epichlorohydrin to it, and add
For 4 hours, the precipitated salt was removed by washing with water to obtain a glycidyl ether group-containing acrylate monomer. Next, 40 parts of the glycidyl ether group-containing acrylate monomer and 60 parts of the styrene monomer were subjected to AIBN.
3 parts and 0.1 part of dodecanethiol are dissolved in 100 parts of xylene and polymerized at 100 ° C. for 4 hours to obtain a glycidyl ether group-containing styrene copolymer (number-average molecular weight 70
00, a xylene solution having 15) propenyl ether groups in the molecule was obtained. 100 parts of this glycidyl ether group-containing styrene polymer and 10 parts of dodecane diacid were reacted at 150 ° C. to obtain a comparative thermosetting resin.

Comparative Example 2 Example 1 was repeated except that nitrophenol was used as the catalyst.
Comparative resin was obtained in the same manner except that 4 parts of -ethylhexyl phosphoric acid was used. When this resin was heated from 100 ° C. to 140 ° C. and heated, the propenyl ether group self-polymerized due to the phosphoric acid ester catalyst to become a thermosetting resin. Did not.

<Evaluation of Resins> Each resin was evaluated by a melt flow rate (method according to JIS K7210) and Rockwell hardness (method according to JIS K7202). In addition, the melt flow rate (MFR) is a load of 2.16 k.
gf / mm, measured at a temperature of 230 ° C. Further, polypropylene (manufactured by Grand Polymer Co., Ltd., product name: J605) was used as a thermoplastic resin standard. Table 1 shows the evaluation results.

[0030]

[Table 1]

The thermally cleavable resin of the present invention exhibited an MFR value higher than that of polypropylene which is a typical thermoplastic resin.
Comparative Example 2 uses a catalyst different from the present invention,
No fluidity was shown even at 230 ° C. Further, it is recognized that the thermally cleavable resin of the present invention has the same hardness as the epoxy-based thermosetting resin of Comparative Example 1 in terms of hardness.

【The invention's effect】

The heat-cleavable resin of the present invention is a specific catalyst which enables a heat-cleavage reaction by introducing a chemical bond causing a reversible addition-cleavage reaction into a molecule as a crosslinked structure, but does not cause self-polymerization as a side reaction. It is recognized that the use of a resin has both high physical properties of a cross-linked resin and excellent moldability of a non-cross-linked resin. Since the thermally cleavable resin of the present invention has a low viscosity at the time of hot melting, a molded article having high physical properties that cannot be obtained with a conventional thermoplastic resin can be obtained while having moldability equivalent to that of a conventional thermoplastic resin. Will be. Also, unlike conventional cross-linkable resins, it is a resin excellent in recyclability because it exhibits thermal cleavability. Examples of molded articles for which the resin composition of the present invention is suitable include fibers, knits, nonwoven fabrics, nets, ropes, films, sheets, plates, bars, various containers, tubes, various parts, and various other molded articles. Can be

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Claims (6)

[Claims] 1. A phenolic compound (C) comprising a compound (A) containing m alkenyl ether groups in the molecule and a compound (B) containing n carboxyl groups in the molecule.
1) or a heat-cleavable resin obtained by performing an addition reaction in the presence of a catalyst comprising hydroxyamine (C2) (where m and n are integers of 2 or more;
And at least one of n is an integer of 3 or more. ) 2. The compound (A) has a hydrocarbon group, an ether group, a thioether group, a carbonyl group,
At least one organic group (a) selected from the group consisting of ester groups, imino groups, amide groups, imide groups, urethane groups, urea groups, carbonate groups, siloxy groups, and groups having a heterocyclic structure containing a nitrogen atom or an oxygen atom; The heat-cleavable resin according to claim 1, comprising: 3. The compound (B) has a hydrocarbon group, an ether group, a thioether group, a carbonyl group,
At least one organic group (b) selected from the group consisting of ester groups, imino groups, amide groups, imide groups, urethane groups, urea groups, carbonate groups, siloxy groups, and groups having a heterocyclic structure containing a nitrogen atom or an oxygen atom; 3. The thermally cleavable resin according to claim 1, which comprises 4. The thermally cleavable resin according to claim 1, wherein said alkenyl ether group is a propenyl ether group or a vinyl ether group. 5. A resin (D) having a divalent chemical bond represented by the following general formula (1) in a molecular chain and a phenol compound (C1) or a hydroxyamine compound (C)
A thermally cleavable resin composition comprising the catalyst of 2). (Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² and R ³ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) 6. The resin (D) comprises a polystyrene resin, an acrylic resin, a polyolefin resin, a polyether resin, a polysiloxane resin, a polycarbonate resin, a polyester resin, a polyamide resin and a polyurethane resin. The thermally cleavable resin composition according to claim 5, which is at least one resin selected from the group.