JPH05202278A - Structural material for acoustic apparatus - Google Patents

Abstract

PURPOSE:To obtain the title material exhibiting a very low shrinkage and excellent in acoustic properties and surface smoothness by incorporating a specified amt. of a specific substance as one of shrink-proofing agents into a thermosetting resin compsn. comprising a thermosetting resin, shrink-proofing agents, and other necessary ingredients. CONSTITUTION:A satd. polyester pref. obtd. by using an acid component mainly comprising a 5-100 aliph. satd. dibasic acid such as adipic acid (e.g. a polyester obtd. from adipic acid, isophthalic acid, and propylene glycol) is incorporated as one of shrink-proofing agents in an amt. of at least 30wt.% of the total amount thereof into a thermosetting resin compsn. comprising a thermosetting resin (e.g. an unsatd. polyester resin), shrink-proofing agents, a catalyst, an internal mold lubricant, an inorg. filler, a fibrous reinforcement, a pigment, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful structural material for audio equipment. More specifically, a thermosetting resin containing a thermosetting resin, a shrinkage reducing agent, a catalyst, an internal mold release agent, an inorganic filler, a fibrous reinforcing material, and the like, and in some cases, a colorant as a main component. The present invention relates to a structural material for an audio device, which is a structural material for an audio device using a composition, and which comprises using a specific compound called a saturated polyester as the shrinkage reducing agent, which is extremely highly practical.

[0002]

2. Description of the Related Art Various types of audio equipment materials have been used for a long time, and it has been a long time, but in recent years, such an audio equipment material is disclosed in, for example, Japanese Unexamined Patent Publication No. 56-138395. As disclosed, by incorporating a large amount of organic fibers in the thermosetting resin composition, a structural material in the form of enhancing the damping effect,

As disclosed in Japanese Patent Laid-Open No. 155256/1982, a so-called scale-like inorganic filler such as mica is blended to form a structural material having an increased internal loss.

Further, as disclosed in Japanese Patent Application Laid-Open No. 55-131052, there is a structural material in which the acoustic characteristics are improved by increasing the specific gravity of the material.

[0005]

In order to improve the acoustic characteristics of such structural materials, it is effective to improve the damping coefficient and elastic modulus, but as a product, the surface smoothness and It is desired that the shrinkage factor at the time of molding is good.

Among the above-mentioned structural materials, JP-A-56-1
As described in Japanese Patent No. 38395, those containing a large amount of organic fibers reduce both elastic modulus and surface smoothness.

Further, as in Japanese Patent Laid-Open No. 155256/1982, a form in which a scaly inorganic filler such as mica is blended deteriorates the fluidity, shrinkage rate and smoothness during molding. It means to let.

Furthermore, as in Japanese Patent Laid-Open No. 55-131052, when the material is made to have a high specific gravity, the elastic modulus increases, but the damping effect does not improve at all. Approximately insufficient.

[0009]

As described above, as long as the conventional technique is followed, the acoustic characteristics, in particular, the attenuation effect can be remarkably improved.
The reality is that it is not possible to obtain a highly practical acoustic device structural material that has low shrinkage and is also excellent in surface smoothness.

In such a situation, the present inventors have
Among various components constituting the thermosetting resin composition, as one of the low-shrinking agents, at least 30% by weight of the total solid content of the low-shrinking agents is a specific compound called saturated polyester. By using, the acoustic characteristics, especially the damping effect, is dramatically increased, and the low shrinkage
Moreover, the inventors have found that an extremely highly practical structural material for audio equipment having excellent surface smoothness can be obtained, and have completed the present invention.

That is, in the present invention, a thermosetting resin, a low-contracting agent, a catalyst, an internal mold release agent, an inorganic filler, a fibrous reinforcing material and the like are used, and in some cases, a coloring agent and the like are main components. An attempt is to provide a structural material for audio equipment, which is a structural material for audio equipment using a thermosetting resin composition, and which comprises using a specific compound called saturated polyester as the shrinkage reducing agent. To do.

That is, by using the structural material having the above-mentioned structure, the acoustic characteristics, especially the damping effect are remarkably enhanced, and in addition, the shrinkage is low and the surface smoothness is excellent. In addition, it has become possible to introduce a structural material for audio equipment that is extremely highly practical.

[0013]

Here, as described above, the saturated polyester, which is one essential component of the resin composition of the present invention, is a mixture of an aliphatic, aromatic or aliphatic saturated dibasic acid or an acid anhydride thereof and glycols. A saturated polyester produced by polycondensation, which is produced by using an aliphatic saturated dibasic acid alone as an acid component, or a combined use of the aliphatic saturated dibasic acid and an aromatic or alicyclic saturated dibasic acid. Is generally referred to as
These dibasic acids are used as ethylenically unsaturated bond-containing vinyl monomers (hereinafter, also referred to as vinyl monomers).
70 to 20 parts by weight of the above is used to obtain the product.

In particular, the saturated polyester is one obtained by using an aliphatic saturated dibasic acid having 5 to 10 carbon atoms as a main acid component. To exemplify only representative examples of the aliphatic dibasic acids, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid or glutaric acid, etc.,
Alternatively, these various esters and the like, on the other hand, phthalic acid, phthalic anhydride, and the like can be cited as only typical examples of aromatic or alicyclic saturated dibasic acids or their acid anhydrides. Acid, isophthalic acid, terephthalic acid, nitrophthalic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, halogenated phthalic anhydride or hexahydrophthalic anhydride, or these various esters, , Which may be used alone or in combination of two or more kinds, and above all, as the aliphatic saturated dibasic acid,
As mentioned above, it is desirable to use C _{5 to} C ₁₀ compounds.

As the glycols, only typical ones are exemplified. Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpropane. , 1,3-diol, neopentyl glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol,
1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, ethylene glycol carbonate, 2,2-di (4-hydroxypropoxydiphenyl) propane, etc., which may be used alone or in combination of two or more, In addition, various oxides such as ethylene oxide or propylene oxide can be used as well. Above all, the use of diethylene glycol would be recommended.

Further, a urethane-modified product of the saturated polyester, an epoxy-modified compound, or the like can be similarly used. As the ethylenically unsaturated double bond-containing vinyl monomer, only typical ones will be exemplified. Styrene, vinyltoluene, α-methylstyrene, chlorostyrene, dichlorostyrene, vinylnaphthalene, ethyl vinyl ether. , Various vinyl compounds such as methyl vinyl ketone, methyl acrylate, ethyl acrylate, methyl methacrylate, acrylonitrile or methacrylonitrile, etc .;

Alternatively, various allylic compounds such as diallyl phthalate, diallyl fumarate, diallyl succinate or triallyl cyanurate are generally used, but it is generally preferable to use a styrene monomer.

Next, the above-mentioned thermosetting resin refers to so-called general-purpose thermosetting resins such as unsaturated polyester resin or vinyl ester resin, and preferably, It is an unsaturated polyester resin.

As the unsaturated polyester resin,
It is produced by polycondensation of unsaturated dibasic acid or acid anhydride thereof, saturated dibasic acid or acid anhydride thereof, and glycols, and in some cases, as an acid component, aliphatic saturated dibasic acid or Examples include those obtained by dissolving 30 to 80 parts by weight of an unsaturated polyester produced by using an aromatic or alicyclic saturated dibasic acid together with 70 to 20 parts by weight of a vinyl-based monomer. .

If necessary, a thickener, a filler, a curing catalyst,
It is used by adding a curing accelerator or a shrinkage reducing agent. Unsaturated dibasic acids or their acid anhydrides are only specifically exemplified, and examples thereof include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid or chloromaleic acid, or , These various esters, etc.,

Specific examples of the aromatic saturated dibasic acids or their acid anhydrides are only phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, nitrophthalic acid and tetrahydrophthalic anhydride. , Endmethylenetetrahydrophthalic anhydride or halogenated phthalic anhydrides, or various esters thereof,

As the aliphatic or alicyclic saturated dibasic acid, only typical ones are exemplified. Oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid,
Examples thereof include azelaic acid, glutaric acid, hexahydrophthalic anhydride, and various esters thereof, and these may be used alone or in combination of two or more kinds.

As the glycols, only typical ones are exemplified, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpropane. , 1,3-diol, neopentyl glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol,
1,6-hexanediol, bisphenol A, hydrogenated bisphenol A or ethylene glycol carbonate, 2,2-di (4-hydroxypropoxydiphenyl) propane, etc., which may be used alone or in combination of two or more, Besides, oxides such as ethylene oxide or propylene oxide can be used as well.

As typical vinyl monomers, only typical ones are exemplified by styrene, vinyltoluene, α-methylstyrene, chlorostyrene, dichlorostyrene, vinylnaphthalene, ethyl vinyl ether, methyl vinyl ketone, Various vinyl compounds such as methyl acrylate, ethyl acrylate, methyl methacrylate, acrylonitrile or methacrylonitrile;

Alternatively, such as various allyl compounds, such as diallyl phthalate, diallyl fumarate, diallyl succinate or triallyl cyanurate, and the like,
Vinyl monomers or vinyl oligomers which can be crosslinked with the unsaturated polyester may be used alone or in combination of two or more, but it is generally preferable to use styrene.

The reaction ratio is such that the unsaturated dibasic acid / saturated dibasic acid molar ratio in the solid composition of the unsaturated polyester is in the range of 1/1 to 1/0, preferably 2 / The range of 1 to 1/0 is suitable.

As the shrinkage reducing agent other than the saturated polyester, a thermoplastic resin is particularly representative, and of these, only representative ones are exemplified by methyl methacrylate and ethyl methacrylate. ,
Various lower alkyl esters of acrylic acid or methacrylic acid such as butyl methacrylate, methyl acrylate or ethyl acrylate;

Various aromatic vinyl monomers such as styrene; various halogenated vinyl monomers such as vinyl chloride; or various vinyl esters such as vinyl acetate. And homopolymers or copolymers of the monomers of

As described above, at least one of various vinyl monomers and lauryl methacrylate or cetylstearyl methacrylate; acrylamide or methacrylamide; hydroxylalkyl-acrylates or -methacrylates; acrylonitrile or methacrylonitrile; And a copolymer with at least one monomer selected from the group consisting of acrylic acid or methacrylic acid,

Alternatively, there may be mentioned cellulose acetate butyrate or cellulose acetate propionate; or polyethylene or polypropylene. The above-mentioned catalyst, which is one essential component of the resin composition of the present invention, refers to a compound that acts on the above-mentioned unsaturated polyester resin, and only typical ones are exemplified as the curing catalyst. If it is limited to tert-butyl perbenzoate, tert-butyl perisopropyl carbonate, tert-peroctoate, benzoyl peroxide or dicumyl peroxide, various organic peroxides, etc., these compounds, respectively These can be used alone or in combination within a range of usually 0.3 to 3 parts by weight relative to 100 parts by weight of the above-mentioned unsaturated polyester resin.

As only one of the essential components of the resin composition of the present invention, the above-mentioned internal mold release agent is particularly representative, various higher fatty acids such as stearic acid or zinc stearate and , Higher fatty acid esters or alkyl phosphates, and the like, which are known and commonly used, these compounds are
Usually, it can be used in a proportion of 0.5 to 5 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

Further, only the typical fillers mentioned above, which are one of the essential components of the resin composition of the present invention, are exemplified, calcium carbonate powder, clay, alumina powder, silica powder, talc, sulfuric acid. Examples of well-known and common ones include barium, silica powder, glass powder, glass beads, mica, aluminum hydroxide, cellulose thread, silica sand, river sand, cold water stone, marble chips or crushed stone. From the aspect, calcium carbonate, aluminum hydroxide and the like are preferable, but in the present invention,
By using clay in combination, more preferable properties can be obtained.

Further, to exemplify only the particularly representative fibrous reinforcing material, which is one of the essential components of the resin composition of the present invention, glass fiber, amide, aramid, vinylon, polyester or phenol can be used. Like,
Various organic fibers; or carbon fibers, metal fibers, ceramic fibers, and the like, and suitable combinations thereof.

In consideration of moldability or economic efficiency, glass fiber or organic fiber is particularly desirable,
Generally, such a fibrous reinforcing material is cut into a range of 3 to 25 mm to form a chop shape.

In the present invention, it is particularly preferable to use glass fiber and vinylon chop together. Furthermore, as the above-mentioned coloring agent used as necessary, of course, conventionally known various organic or inorganic dyes and pigments can be used, but among them, heat resistance and transparency are excellent. Moreover, it is desirable to use a resin that does not significantly hinder the curing of the unsaturated polyester resin.

The molded article obtained by using the structural material of the present invention and applicable to the speaker,
Various parts such as boxes or speaker frames, covers for audio or video equipment, chassis, mechanical parts, etc. can be mentioned.

[0037]

EXAMPLES Next, the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified. .

Reference Example 1 (Preparation Example of Unsaturated Polyester Resin) An unsaturated polyester was prepared from 1 mol of propylene glycol and 1 mol of maleic acid by a conventional method, and the resin solid content was 60 with styrene monomer. % To obtain a target resin solution which is a styrene monomer solution of unsaturated polyester. Hereinafter, this is an unsaturated polyester resin UP
It is abbreviated as E-1.

Reference Example 2 (Same as above) According to a conventional method, from 1 mol of hydrogenated bisphenol A, 2 mol of ethylene glycol and 3 mol of maleic acid,
An unsaturated polyester was prepared, and a target resin solution, which was a styrene monomer solution of the unsaturated polyester and had a resin solid content of 60%, was obtained with the styrene monomer. Less than,
This is abbreviated as unsaturated polyester resin UPE-2.

Reference Example 3 (Preparation Example of Saturated Polyester) By a conventional method, 1 mol of isophthalic acid and 1 mol of adipic acid were used.
A saturated polyester was prepared from 2 mol of propylene glycol and 2 mol of propylene glycol to obtain a target resin solution which was a styrene monomer solution of saturated polyester having a resin solid content of 40% with a styrene monomer. Hereinafter, this is abbreviated as saturated polyester resin PE-1.

Reference Example 4 (Same as above) By a conventional method, 1 mol of isophthalic acid and 1 mol of adipic acid were used.
A saturated polyester was prepared from 1 mol of ethylene glycol and 2 mol of ethylene glycol to obtain a target resin solution which was a styrene monomer solution of saturated polyester having a resin solid content of 40% with styrene monomer. Hereinafter, this is abbreviated as saturated polyester resin PE-2.

Reference Example 5 (Same as above) By a conventional method, 1 mol of isophthalic acid and 1 mol of adipic acid were used.
Mol, 1 mol of sebacic acid, and 4 mol of ethylene glycol were used to prepare a saturated polyester, and a target resin solution was obtained, which was a styrene monomer solution of saturated polyester having a resin solid content of 40% with styrene monomer. . Hereinafter, this is abbreviated as saturated polyester resin PE-3.

Reference Example 6 (Same as above) A saturated polyester was prepared from 1 mol of adipic acid and 1 mol of diethylene glycol by a conventional method, and the resin solid content was 50% by the styrene monomer. A target resin solution, which is a solution, was obtained. Hereinafter, this is abbreviated as saturated polyester resin PE-4.

Reference Example 7 (Preparation Example of Shrinkage Reducing Agent) “Dick Styrene CR-3500” [polystyrene of Dainippon Ink and Chemicals, Inc.] has a resin solid content of 4
A 0% styrene monomer solution was prepared. Hereinafter, this is abbreviated as a low-contraction agent LPA-1.

Reference Example 8 (same as above) A styrene monomer solution of "SN-04" [polyvinyl acetate manufactured by Denki Kagaku Kogyo] having a resin solid content of 30% was prepared. Hereinafter, this is abbreviated as low-contraction agent LPA-2.

Example 1 A target thermosetting resin composition was prepared by the following formulation. Incidentally, such a mixture, by a kneader,
The resin composition was prepared by mixing at room temperature.

Unsaturated Polyester Resin UPE-1 120 Saturated Polyester Resin UP-1 80 Tertiary Butyl Perbenzoate 2 Zinc Stearate 20 Calcium Carbonate Powder 600 6 mm Glass Chopped Strands 180

Example 2 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-2 120 Saturated polyester resin UP-2 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 mm length glass chopped strand 180

Example 3 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-2 120 Saturated polyester resin UP-2 60 Low shrinkage agent LPA-1 20 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 mm long glass chopped strands 180

Example 4 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-2 120 Saturated polyester resin UP-2 60 Low shrinkage agent LPA-1 20 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 mm long glass chopped strands 120 3 mm long vinylon Fiber 25

Example 5 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-2 120 Saturated polyester resin UP-2 40 Low shrinkage agent LPA-1 40 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 300 Clay powder 200 Glass chopped strand with a length of 6 mm 180

Example 6 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-2 120 Saturated polyester resin UP-2 40 Low shrinkage agent LPA-2 40 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 mm length glass chopped strands 180

Example 7 A target thermosetting resin composition was prepared by the following formulation. Unsaturated polyester resin UPE-1 120 Saturated polyester PE-3 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 3 Glass chopped strands with a length of 3 180

Example 8 A target thermosetting resin composition was prepared by the following formulation. Unsaturated Polyester Resin UPE-1 120 Saturated Polyester PE-4 80 Tertiary Butyl Perbenzoate 2 Zinc Stearate 20 Calcium Carbonate Powder 600 3 mm Glass Chopped Strand 180

COMPARATIVE EXAMPLE 1 The use of saturated polyester was completely eliminated,
A thermosetting resin composition for control was prepared in the same manner as in Example 1 except that the following formulation was changed. Unsaturated polyester resin UPE-1 120 Low-contraction agent LPA-1 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 Glass chopped strands with a length of 180

Comparative Example 2 Without any use of saturated polyester,
A thermosetting resin composition for control was prepared in the same manner as in Example 1 except that the following formulation was changed. Unsaturated polyester resin UPE-1 120 Low-contraction agent LPA-2 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 Glass chopped strands with a length of 180

Comparative Example 3 Without any use of saturated polyester,
A thermosetting resin composition for control was prepared in the same manner as in Example 2 except that the formulation was changed as follows. Unsaturated polyester resin UPE-2 120 Low-contraction agent LPA-1 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 Glass chopped strands with a length of 180

COMPARATIVE EXAMPLE 4 The use of saturated polyester was totally omitted.
A thermosetting resin composition for control was prepared in the same manner as in Example 2 except that the formulation was changed as follows. Unsaturated polyester resin UPE-2 120 Low shrinkage agent LPA-2 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 600 6 Glass chopped strands with a length of 180

Comparative Example 5 Example 1 except that the following formulation was changed as a preparation example when organic fibers were blended as in the invention described in JP-A-56-138395. A thermosetting resin composition for control was prepared in the same manner as in.

Unsaturated polyester resin UPE-2 120 Low shrinkage agent LPA-1 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 500 6 mm long glass chopped strands 80 3 mm long vinylon fibers 50

Comparative Example 6 As a preparation example in the case of incorporating mica as in the invention described in JP-A-57-155256,
A thermosetting resin composition for control was prepared in the same manner as in Example 1 except that the following formulation was changed.

Unsaturated polyester resin UPE-2 120 Low shrinkage agent LPA-1 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Calcium carbonate powder 300 Mica powder 150 6 mm long glass chopped strands 180

Comparative Example 7 As in the invention described in Japanese Patent Application Laid-Open No. 55-131052, as a preparation example in the case of so-called high specific gravity, Example 1 except that the following formulation was changed. A thermosetting resin composition for control was prepared in the same manner as in.

Unsaturated polyester resin UPE-2 120 Low shrinkage agent LPA-1 80 Tertiary butyl perbenzoate 2 Zinc stearate 20 Alumina powder 900 6 mm length glass chopped strand 180

The respective resin compositions of Examples 1, 2 and 3 were treated at 150 ° C. and 30 kgf / cm ² , and
A speaker box, which is a structural material for audio equipment, was obtained by heating and pressurizing for 2 minutes.

Then, using the plate cut out from the box thus obtained, evaluation tests of various characteristics and performances were carried out, and the following results were obtained.

[0067]

[Table 1]

<< Footnote in Table 1 >> The loss coefficient is obtained from the vibration test of the cantilever, the surface smoothness is obtained by visual judgment, and the fluidity is When a certain amount of material was compression molded with a flat plate at a constant speed, the flowed area was expressed as a ratio based on Comparative Example 1, and the larger the area,
It shows that the flow is good.

Furthermore, the elastic modulus is based on a bending test.

[0070]

Industrial Applicability The structural material for audio equipment obtained by using the resin composition of the present invention having the constitution as described in detail above has a dramatically improved acoustic characteristic, especially, the damping effect. In addition, it has low shrinkage and is also excellent in surface smoothness, which is extremely practical.

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Claims (2)

[Claims] 1. A thermosetting resin composition containing a thermosetting resin, a low-contracting agent, a catalyst, an internal mold release agent, an inorganic filler, a fibrous reinforcing material and the like, and optionally a coloring agent and the like. Which is a structural material for an audio device, wherein saturated polyester as one of the above-mentioned low-shrinking agents is contained in the solid content of all the low-shrinking agents in an amount of 30% by weight or more. Structural materials for equipment. 2. The audio equipment according to claim 1, wherein the saturated polyester resin is obtained by using, as an acid component, an aliphatic saturated dibasic acid having 5 to 10 carbon atoms as a main component. Structural material.