JP2003176341A - Polyester resin for molding, resin composition and molded article produced by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin or resin composition for the molding of electric or electronic parts having complicate shapes and sufficiently satisfying various properties such as waterproofness, electrical insulation, working environment, productivity and durability. <P>SOLUTION: The saturated polyester resin for molding has a melt viscosity of 5-1,000 dPas at 200°C and an a×b value of ≥500 wherein (a) (N/mm<SP>2</SP>) is the tensile strength at break of a film molded by the resin and (b) (%) is the tensile elongation at break. The invention further relates to a molded article produced by using the resin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin for molding, a resin composition and a molded article using the same. INDUSTRIAL APPLICABILITY The polyester resin and resin composition of the present invention are suitable for low-pressure molding applications for fixing and waterproofing electric and electronic parts.

[0002]

2. Description of the Related Art Electrical and electronic parts widely used in automobiles and electric appliances are required to have electrical insulation from the outside in order to achieve their intended use. For example, the electric wire is covered with a resin having an electric insulation property. In recent years, a variety of methods have been adopted for the electric insulation in the midst of a rapid increase in applications such as mobile phones, in which complicated electric / electronic parts need to be packed in a small capacity. In particular, when a resin or the like to be an electrical insulator is molded on a component having a complicated shape such as a circuit board, a method capable of following the shape is required. For that purpose, a method of decreasing the viscosity of the resin at the time of coating is common. A method of previously dissolving a resin in a solvent to form a solution, impregnating an electric / electronic component, and then evaporating the solvent is one of methods of decreasing the viscosity, but when the solvent evaporates, bubbles remain or the solvent remains. If an organic solvent is used as the above, the working environment becomes poor and there are many problems.

Therefore, up to now, in consideration of durability after molding, a two-component epoxy resin has been generally used as proposed in many documents (for example, Patent Documents 1 and 2). reference). In this method, a main agent and a curing agent are mixed at a certain ratio immediately before molding, molded at a low viscosity, heated and stored for several days to accelerate the curing reaction and completely solidify. However, in this method, it is pointed out that the epoxy resin has an adverse effect on the environment, it is necessary to precisely adjust the mixing ratio of the two liquids, and the usable period before mixing is limited to 1 to 2 months. The problem is known. Further, since curing requires a curing period of several days, there is a problem that productivity is low. further,
There is also a problem that stress due to resin shrinkage after curing concentrates on a portion having a low physical strength, such as a solder portion for joining an electric / electronic component and a conductive wire, and peels off the portion.

A hot melt type resin is used as a molding resin instead of the two-component epoxy resin which has been used in view of the above problems. The hot melt adhesive, which only heats and melts the resin to reduce the viscosity at the time of molding, solves the problem of working environment in the solvent-containing system and the epoxy resin system. In addition, since the solidification is achieved by simply cooling after the molding, the productivity is increased. In addition, since a thermoplastic resin is generally used, the members can be easily recycled by heating and melting and removing the resin even after the life of the product is finished. However, the reason why it has not been a material that can sufficiently replace the two-pack epoxy resin so far while having a high potential as a molding resin is that a material suitable for it has not been proposed.

For example, ethylene vinyl acetate (EVA), which is relatively inexpensive as a hot melt, has insufficient heat resistance, does not have durability in the environment where electric and electronic parts are used, and exhibits adhesiveness. Therefore, since various additives are contained, the electric performance may be deteriorated due to contamination of the electric and electronic parts, which is not suitable. Polyamide, which expresses high adhesion to various materials with a resin alone, is excellent as a low-pressure molding resin material due to its low melt viscosity and high resin strength (for example, Patent Document 3).
In general, the hygroscopicity is high, and the moisture is gradually absorbed from the outside, so that the electrical insulation property, which is the most important characteristic, is often deteriorated with time.

On the other hand, polyester, which has both high electric insulation and high water resistance, is considered to be a very useful material for this purpose, but it generally has a high melt viscosity, and is several thousand N / cm ² or more for molding into complicated parts. Since high-pressure injection molding is required, electric and electronic parts may be destroyed during molding.

As described above, in the prior art, no material has been proposed as a molding resin for electric / electronic parts having a complicated shape, which sufficiently satisfies various performances.

[0008]

[Patent Document 1] JP-A-1-75517 ([Claims] and others)

[Patent Document 2] Japanese Unexamined Patent Publication No. 2000-239349 ([Claims] and others)

[Patent Document 3] European Patent No. 1052595 (pages 6 to 8, [Claims], etc.)

[0009]

The present invention has been made to solve the above problems, and an object of the present invention is as a molding polyester resin or resin composition for electric and electronic parts having a complicated shape. , To provide materials that sufficiently satisfy various performances such as waterproofness, electrical insulation, working environment, productivity, and durability.

[0010]

[Means for Solving the Problems] To achieve the above object,
The present inventors have made extensive studies and have proposed the following invention. That is, the present invention is the following polyester resin for molding, a resin composition, and a molded product using the same.

(1) The melt viscosity at 200 ° C. is 5 to 100.
It is 0 dPa · s or less, the tensile breaking strength of the film-shaped molded product is a (N / mm ² ), and the tensile breaking elongation is b.
A saturated polyester resin for molding, characterized in that the product a × b in terms of (%) is 500 or more.

(2) A saturated polyester resin for molding, which has a glass transition temperature of -10 ° C or lower and a melting point of 70 ° C to 200 ° C.

(3) The ester group concentration of the polyester is 1
000-8000 equivalent / 10 ⁶ g, saturated polyester resin for molding.

(4) A saturated polyester resin for molding, wherein 2 mol% or more of the diol component of the polyester is polyalkylene glycol when the total amount of the diol component of the polyester is 100 mol%.

(5) The saturated polyester resin for molding according to (4), wherein the polyalkylene glycol is polytetramethylene glycol having a number average molecular weight of 400 to 10,000.

(6) When the total amount of the diol component of the polyester is 100 mol%, 2 mol% or more of the diol component of the polyester is an aliphatic and / or alicyclic glycol having 10 or more carbon atoms. A characteristic saturated polyester resin for molding.

(7) When the total amount of the dicarboxylic acid component of the polyester is 100 mol%, 2 mol% or more of the dicarboxylic acid component of the polyester is an aliphatic and / or alicyclic dicarboxylic acid having 10 or more carbon atoms. A saturated polyester resin for molding, which is characterized by being present.

(8) Dicarboxylic acid component of polyester,
When the total amount of each of the diol components is 100 mol%, 60 mol% or more of the dicarboxylic acid component is terephthalic acid and / or naphthalene dicarboxylic acid, and 40 mol% or more of the diol component is 1,4- The saturated polyester resin for molding according to any one of (1) to (7), which is butanediol and / or ethylene glycol.

(9) A polyester resin composition for molding, characterized by containing 50% by weight or more of the saturated polyester resin according to any one of (1) to (8).

(10) A polyester resin composition for molding which comprises the saturated polyester resin according to any one of (1) to (8) and an antioxidant.

(11) 100 hours, 121 ° C., 0.2M
The retention rate of melt viscosity after the heat treatment test in Pa is
A polyester resin composition for molding, which has a melt viscosity of 70% or more before the heat treatment test.

(12) Melt viscosity at 200 ° C. is 5 to 10
It is 00 dPa · s, and the tensile breaking strength of the film-shaped molded product is a (N / mm ² ) and the tensile breaking elongation is b (%).
And the product a × b is 500 or more.

(13) A molded product using the saturated polyester resin for molding according to any one of (1) to (8).

(14) A molded product using the polyester resin composition for molding according to any of (9) to (12).

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The molding referred to in the present invention is molding which is injected at a low pressure of 10 to 800 N / cm ² . That is, this is a molding method performed at a very low pressure, as compared with injection molding at a high pressure at an average of about 4000 N / cm ² which has been conventionally used for molding plastics. In principle, similar to normal injection molding, molten resin is injected into a mold with electrical and electronic parts set to wrap the parts, and overmolding can be done without destroying delicate parts. It is possible.

The molding polyester resin of the present invention preferably has a melt viscosity at 200 ° C. of 5 to 1000 dPa · s. Here, the melt viscosity at 200 ° C. is a value measured as follows. Using a sample dried to a water content of 0.1% or less, a flow tester (model number CFT-500C) manufactured by Shimadzu Corporation at 200 ° C.
The viscosity of the polyester resin that was heated and stable was passed through a die with a hole diameter of 1.0 mm and a thickness of 10 mm at a pressure of 98 N / cm ² , and the viscosity was measured. 1000 dPa · s
When the above-mentioned high melt viscosity is obtained, high resin cohesive force and durability can be obtained, but since high-pressure injection molding is required for molding into a complicated shape, parts may be destroyed. 1000 dPa · s or less, preferably 500 dPa
-By using a molding polyester having a melt viscosity of s or less, a relatively high injection pressure of several hundred N / cm ² can be obtained to obtain a molded component having excellent electrical insulation properties, as well as characteristics of an electrical / electronic component. Does not hurt. Also, 200
The melt viscosity at 0 ° C. is preferably low, but considering the adhesiveness and cohesive force of the resin, the lower limit is preferably 5 dPa · s or more, more preferably 10 dPa · s or more, more preferably 50 dPa · s or more, and most preferably 100
It is preferably dPa · s or more.

Further, in order to mold the polyester without causing thermal deterioration as much as possible, rapid melting at 210 to 220 ° C. is required, so the upper limit of the melting point is 200.
℃ is desirable. Preferably 190 ° C., more preferably 1
It is 80 ° C. The lower limit is preferably 5 to 10 ° C. higher than the heat resistant temperature required for the corresponding application. Considering the handling property at normal temperature and the usual heat resistance, the temperature is 70 ° C or higher, more preferably 100 ° C or higher, further preferably 120 ° C or higher, particularly preferably 140 ° C or higher, most preferably 150 ° C or higher.

In the polyester of the present invention, the tensile breaking strength and the elongation are measured at 23 ° C. and 50% RH atmosphere by molding a film formed by hot pressing. Specifically, a dried polyester resin having a water content of 0.1% or less is sandwiched between two sheets of polyfluorinated ethylene, and
After heat-pressing at 0 ° C. for 10 seconds, it is rapidly cooled to room temperature to obtain a polyester film. At this time, the thickness is 0.2 mm
It is desirable to use a spacer as necessary to adjust the temperature. The tensile rupture strength and elongation referred to in the present invention are obtained by cutting out a sample having a length of 50 mm and a width of 15 mm from such a film, and chuck distance is 30 mm, 23 ° C.
It is measured at a pulling speed of 50 mm / min in a 0% RH atmosphere. The tensile breaking strength at this time is a (N / m
m ² ), and the product a × b when the tensile elongation at break is b (%) is preferably 500 or more. The product a × b is more preferably 1000 or more, still more preferably 2000 or more, and most preferably 2500 or more. Product a × b is 1
If it is less than 000, it may not be possible to have sufficient durability against various impacts received under various use conditions. On the other hand, although the upper limit is not particularly limited, it is 20,000 or less, more preferably 15,000 or less, and most preferably 12,000 or less in consideration of the resin strain on the electronic components inside.

If the tensile breaking strength is low, electric
Parts cannot be retained with sufficient strength and may fall off
Therefore, the tensile breaking strength a is preferably 2 (N /
mm ²) That is all. If the tensile elongation at break is low, the resin
The brittleness of the tree could not withstand the mechanical load of electric and electronic parts,
Since it may cause oil cracks, it is preferable that
The tensile elongation at break b is 200 (%) or more.

As described above, the polyester exhibits the low melt viscosity not found in polyesters such as PET and PBT generally used in engineering plastics, and the heat resistance and durability comparable to that of a two-component epoxy resin. Therefore, it is necessary to adjust the composition of the aliphatic system and / or the alicyclic system and the aromatic system. For example, in order to maintain high heat resistance of 150 ° C. or higher, terephthalic acid and ethylene glycol, terephthalic acid and 1,4-butanediol, naphthalenedicarboxylic acid and ethylene glycol, naphthalenedicarboxylic acid and 1,4-butanediol are used. Copolymerized polyesters based are suitable. In particular, the mold releasability due to rapid crystal solidification after molding is a desirable property from the viewpoint of productivity, so that terephthalic acid and 1,4-
It is preferably based on butanediol, naphthalenedicarboxylic acid and 1,4-butanediol.

Either one or both of terephthalic acid and naphthalenedicarboxylic acid are preferably contained in the dicarboxylic acid component in an amount of 60 mol% or more, more preferably 70 mol% or more, and particularly 80 mol% or more. It is preferable. Further, one or both of ethylene glycol and 1,4-butanediol is preferably 40 mol% or more, more preferably 45 mol% or more, and particularly 50 mol% in the acid component in the diol component. The above is preferable, and the most preferable is 55 mol% or more.

When the total sum of all dicarboxylic acid components and all diol components is 200 mol%, terephthalic acid and 1,
The total amount of 4-butanediol is preferably 120 mol% or more, more preferably 130 mol% or more, further preferably 140 mol% or more, and most preferably 15 mol% or more.
It is 0 mol% or more. If it is less than 120 mol%, the crystallization rate tends to be slow, and the releasability from the mold tends to decrease. The total amount of naphthalenedicarboxylic acid and 1,4-butanediol is preferably 120 mol% or more,
More preferably 130 mol% or more, still more preferably 1
It is 40 mol% or more, particularly preferably 150 mol% or more. If it is less than 120 mol%, the crystallization rate tends to be slow, and the releasability from the mold tends to decrease. In either case, the upper limit is 180 mol%, preferably 170 mol%. If it exceeds 180 mol%, the crystallization rate is too fast, so that strain at the time of contraction is likely to occur, and the adhesion to electric / electronic parts may be deteriorated.

As a copolymerization component for imparting adhesiveness to the base composition giving these high heat resistance, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexane Aliphatic or alicyclic dicarboxylic acids such as dicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dimer acid, hydrogenated dimer acid, 1,2-propanediol, 1 , 3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,5
-Pentanediol, 1,6-hexanediol, 3-
Methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecanedimethanol, neopentylglycol hydroxypivalic acid Aliphatic or alicyclic glycols such as esters, 1,9-nonanediol, 2-methyloctanediol, 1,10-dodecanediol, 2-butyl-2-ethyl-1,3-propanediol and polyoxymethylene glycol Is mentioned.

Further, aliphatic or alicyclic dicarboxylic acids having 10 or more carbon atoms such as dimer acid and hydrogenated dimer acid, and derivatives thereof, or aliphatic groups having 10 or more carbon atoms such as dimer diol and hydrogenated dimer diol, Copolymerization of a / or an alicyclic diol can lower the glass transition temperature while maintaining a high melting point. Therefore, from the viewpoint of achieving both the heat resistance of the polyester resin and the adhesion to electric and electronic parts, It is preferably contained as a dicarboxylic acid component or a diol component at the time of copolymerization. The derivative of an aliphatic and / or alicyclic dicarboxylic acid means a derivative of a carboxylic acid which can be a copolymerization component, such as an ester or an acid chloride.

Here, the dimer acid means an aliphatic or alicyclic dicarboxylic acid (unlike most dimers, trimers and monomers) produced by dimerization of unsaturated fatty acids by polymerization or Diels-Alder reaction. Etc. are often contained) and the hydrogenated dimer acid means the one obtained by adding hydrogen to the unsaturated bond portion of the dimer acid. Also,
The dimer diol and hydrogenated dimer diol are those obtained by reducing the two carboxyl groups of the dimer acid or the hydrogenated dimer acid to hydroxyl groups. Examples of the dimer acid or dimer diol include Enpol or Sobamol manufactured by Cognis or Pripol manufactured by Unichema.

Also, a small amount of an aromatic copolymerization component can be used as long as it maintains a low melt viscosity. For example,
Examples thereof include aromatic dicarboxylic acids such as isophthalic acid and orthophthalic acid, and aromatic glycols such as ethylene oxide adducts and propylene oxide adducts of bisphenol A. In particular, from the viewpoint of mold releasability, it is possible to introduce a dimer acid, dimer diol, or an aliphatic component having a relatively high molecular weight such as polytetramethylene glycol in a block, which shows rapid crystal solidification after molding. preferable.

The introduction of these block-like polymers improves the thermal cycle durability by lowering the glass transition temperature and the hydrolysis resistance by lowering the ester group concentration. Is a more preferable measure when is important. The cold-heat cycle durability referred to here is the ability to raise and lower the temperature between high temperature and low temperature many times to prevent resin peeling or resin cracking at the interface with electronic components having different linear expansion coefficients. . If the elastic modulus of the resin increases during cooling, peeling or cracking is likely to occur. The glass transition temperature is preferably −10 ° C. or lower in order to provide a material that can endure a thermal cycle. It is more preferably -20 ° C or lower, further preferably -40 ° C or lower, and most preferably -50 ° C or lower. The lower limit is not particularly limited, but in consideration of adhesiveness and blocking resistance, it is −100.
The temperature above ℃ is realistic.

In order to impart long-term durability and hydrolysis resistance to withstand high temperature steam, the upper limit of the ester group concentration is preferably 8000 equivalent / 10 ⁶ g. A preferred upper limit is 7500 equivalents / 10 ⁶ g, and more preferably 7000 equivalents / 10 ⁶ g. Further, in order to secure the chemical resistance as a polyester (gasoline, engine oil, alcohol, general-purpose solvent, etc.), the lower limit is preferably 1000 equivalents / 10 ⁶ g. The preferred lower limit is 1500 equivalents / 10 ⁶ g, more preferably 20.
It is 00 equivalent / 10 < ⁶ > g. Here, the unit of the ester group concentration is represented by the number of equivalents per 1 t of resin, and is a value calculated from the composition of the polyester resin and its copolymerization ratio.

In introducing the block polymer, dimer acid, hydrogenated dimer acid, dimer diol, hydrogenated dimer diol and polytetramethylene glycol are preferably 2 mol% or more, more preferably 5 mol%. , More preferably 10 mol% and most preferably 20 mol% or more. The upper limit is 70 mol% or less, preferably 60 mol% or less, and more preferably 50 mol% or less, in consideration of handleability such as heat resistance and blocking. The number average molecular weight of polytetramethylene glycol is 4
It is preferably 00 or more, more preferably 500.
Or more, more preferably 600 or more, and particularly preferably 7
It is at least 00, and the upper limit is preferably 10,000, more preferably 6000, further preferably 4000, and particularly preferably 3000. When the number average molecular weight of polytetramethylene glycol is less than 400, the thermal cycle durability and the hydrolysis resistance may decrease. While 10
When it exceeds 000, the compatibility with the polyester portion is lowered, and it may be difficult to copolymerize in a block form.

The number average molecular weight of the polyester is preferably 3,000 or more, more preferably 5,000 or more, still more preferably 7,000 or more. The upper limit of the number average molecular weight is preferably 50,000 or less, more preferably 40,000 or less, still more preferably 30,000 or less. If the number average molecular weight is less than 3000, the product a
It is difficult for the value of xb to satisfy the specified value, and if it exceeds 50,000, the melt viscosity at 200 ° C. may increase.

The molding polyester resin of the present invention is preferably a saturated polyester resin containing no unsaturated group. If it is unsaturated polyester,
There is a possibility that crosslinking may occur during melting, and the melt stability during molding may be poor.

If necessary, a polycarboxylic acid such as trimellitic anhydride or trimethylolpropane or a polyol may be copolymerized.

As a method for determining the composition and composition ratio of the polyester resin of the present invention, for example, ¹ H-NMR measured by dissolving the polyester resin in a solvent such as deuterated chloroform
And ¹³ C-NMR, quantitative determination by gas chromatography measured after methanolysis of polyester resin, and the like. Of these, ¹ H-NMR is simple and preferred.

As the method for producing the polyester resin of the present invention, a known method can be used. For example, after the esterification reaction of the above dicarboxylic acid and diol components at 150 to 250 ° C., 230 to 300 under reduced pressure is performed. The target polyester can be obtained by polycondensation at ℃. Alternatively, the derivative such as dimethyl ester of dicarboxylic acid and the diol component are used at 150 ° C to 25 ° C.
After transesterification at 0 ° C, the pressure is reduced to 230 ° C to 3
The target polyester can be obtained by polycondensation at 00 ° C.

The molding polyester resin of the present invention includes polyesters, polyamides, polyolefins, epoxies, polycarbonates, acrylics, ethylene vinyl acetate, phenols, etc. having other compositions for the purpose of improving adhesion, flexibility, durability and the like. Other resins, isocyanate compounds, curing agents such as melamine, fillers such as talc and mica, carbon black, pigments such as titanium oxide, antimony trioxide, flame retardants such as brominated polystyrene, as a resin composition It can be used for molding purposes. The polyester content in that case is preferably 50% by weight or more, more preferably 60% by weight or more, further preferably 70% by weight, particularly preferably 90% by weight or more, based on the entire composition. When the content of polyester is less than 50% by weight, the excellent fixing and adhesion of electric and electronic parts, various durability and water resistance of the polyester resin itself may be deteriorated.

Further, when the polyester resin or resin composition of the present invention is exposed for a long time at a high temperature for molding, it is preferable to add an antioxidant. For example,
As a hindered phenol type, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl)
Isocyanurate, 1,1,3-tri (4-hydroxy-2-methyl-5-t-butylphenyl) butane, 1,
1-bis (3-t-butyl-6-methyl-4-hydroxyphenyl) butane, 3,5-bis (1,1-dimethylethyl) -4-hydroxy-benzenepropanoic acid, pentaerythrityl tetrakis ( 3,5-di-t
-Butyl-4-hydroxyphenyl) propionate,
3- (1,1-dimethylethyl) -4-hydroxy-5
-Methyl-benzenepropanoic acid, 3,9-bis [1,1-dimethyl-2-[(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4 , 8,10-Tetraoxaspiro [5.
5] Undecane, 1,3,5-trimethyl-2,4,6
-Tris (3 ', 5'-di-t-butyl-4'-hydroxybenzyl) benzene, phosphorus-based 3,9-bis (p-nonylphenoxy) -2,4,8,10-tetraoxa-3 , 9-Diphosphaspiro [5.5] undecane, 3,9-bis (octadecyloxy) -2,4
8,10-Tetraoxa-3,9-diphosphaspiro [5.5] undecane, tri (monononylphenyl) phosphite, triphenoxyphosphine, isodecylphosphite, isodecylphenylphosphite, diphenyl2-ethylhexyl Phosphite, dinonylphenylbis (nonylphenyl) ester phosphoric acid, 1,1,3-tris (2-methyl-4-ditridecylphosphite-5-t-butylphenyl)
Butane, tris (2,4-di-t-butylphenyl) phosphite, pentaerythritol bis (2,4-di-t-butylphenylphosphite), 2,2′-methylenebis (4,6-di-t) -Butylphenyl) 2-ethylhexylphosphite, bis (2,6-di-t-
Butyl-4-methylphenyl) pentaerythritol
Diphosphite, thioether-based 4,4′-thiobis [2-t-butyl-5-methylphenol] bis [3- (dodecylthio) propionate], thiobis [2- (1,1-dimethylethyl) -5- Methyl-4,
1-phenylene] bis [3- (tetradecylthio) -propionate], pentaerythritol tetrakis (3
-N-dodecyl thiopropionate) and bis (tridecyl) thiodipropionate can be mentioned, and these can be used alone or in combination. The added amount is preferably 0.1% or more and 5% or less. If it is less than 0.1%, the effect of preventing thermal deterioration may be poor. If it exceeds 5%, the adhesion may be adversely affected.

The polyester resin composition of the present invention comprises 10
It is desirable that the retention rate of the melt viscosity after the heat treatment test at 121 ° C. and 0.2 MPa for 0 hours is 70% or more with respect to the melt viscosity before the heat treatment test. The heat treatment test referred to here is to cut a resin or a composition thereof for molding into a size of 1 cm × 1 cm × 1 cm, and
It is assumed that the treatment is performed under the conditions of 21 ° C. × 0.2 MPa × 100 hours. The melt viscosity retention ratio at this time is preferably 75
% Or more, more preferably 80% or more, most preferably 9% or more.
It is 0% or more. There is no upper limit, and the closer to 100% the better. When the melt viscosity retention rate is less than 70%, the durability in use at high temperature may be reduced.

The molding polyester resin or resin composition of the present invention is molded by injecting it into a mold in which electric and electronic parts are set. More specifically, it is heated and melted at around 130 to 220 ° C. in a heating tank, injected into a mold through an injection nozzle, and after a certain cooling time, the molded product is removed from the mold to form a molded product. You can get it.

The molding equipment is not particularly limited. For example, Mold-man manufactured by US Cavist Co., Ltd.
8000, Nordson, Germany WS102 / MX
3006, Dynamelt series manufactured by ITW Dynatec, Inc., USA, and the like.

[0050]

EXAMPLES The following examples are given to describe the present invention in more detail, but the present invention is not limited to the examples. In addition, each measured value described in the examples is measured by the following method.

Melting point, glass transition temperature: With a differential scanning calorimeter "DSC220 type" manufactured by Seiko Denshi Kogyo Co., Ltd., 5 mg of a measurement sample was placed in an aluminum pan, and the lid was pressed and sealed, once at 250 ° C. for 5 minutes. Hold and melt the sample completely, then quench with liquid nitrogen, then -150 ℃
To 250 ° C. at a heating rate of 20 ° C./min. The inflection point of the obtained curve was taken as the glass transition temperature, and the endothermic peak was taken as the melting point.

Melt viscosity: A flow tester (CFT-500C type, manufactured by Shimadzu Corporation) was used to fill a cylinder in the center of the heating element set at 200 ° C. with a resin sample dried to a moisture content of 0.1% or less and to fill it. After 1 minute, a load (98 N) is applied to the sample through the plunger, the molten sample is extruded from the die (hole diameter: 1.0 mm, thickness: 10 mm) at the bottom of the cylinder, and the plunger descending distance and descending time. Was recorded and the melt viscosity was calculated.

Tensile breaking strength, tensile breaking elongation: A polyester sheet (width 15 mm, thickness 0.2 mm, length 50 mm) was prepared in advance, and the tensile breaking strength and tensile breaking elongation at 23 ° C. and 50% RH were measured. The distance between chucks was 30 mm, and the pulling speed was 50 mm / min.

Number average molecular weight: Gel permeation chromatography (GP, manufactured by Waters) using chloroform as an eluent
C) Using 150c, column temperature 35 ° C., flow rate 1 cm
^It was calculated from the result of GPC measurement at ³ / min to obtain a polystyrene-converted measured value.

Melt viscosity retention rate before and after heat treatment test: A sample was cut into 1 cm x 1 cm x 1 cm, and the sample was cut by a pressure cooker tester manufactured by Tabai Espec Co., Ltd.
Processed in TTC-411. The retention rate was calculated by comparing the melt viscosities before and after the heat treatment test. The melt viscosity was measured according to the method described above.

Production Example of Polyester Resin 166 parts by weight of terephthalic acid and 18 parts of 1,4-butanediol are placed in a reactor equipped with a stirrer, a thermometer, and a distilling cooler.
0 parts by weight and 0.25 parts by weight of tetrabutyl titanate were added, and an esterification reaction was carried out at 170 to 220 ° C. for 2 hours. After the completion of the esterification reaction, 300 parts by weight of polytetramethylene glycol "PTMG1000" having a number average molecular weight of 1000 (manufactured by Mitsubishi Chemical Corporation) and 0.5 parts of a hindered phenolic antioxidant "Irganox 1330" (manufactured by Ciba Geigy) are used. Pour in parts by weight and raise the temperature to 255 ° C. while gradually reducing the pressure in the system to 25
The pressure was 665 Pa at 5 ° C. Then, the polycondensation reaction is further performed at 133 Pa or less for 30 minutes to obtain the polyester resin (A).
Got The melting point of this polyester resin (A) is 165 ° C.
The melt viscosity was 250 dPa · s.

The polyester resins (B) to (K) were synthesized in the same manner as the polyester resin (A). Table 1 shows each composition and physical property value.

The polyester resins (A) to (H) meet the claims of this patent, while the polyester resin (I) is 2
Regarding the melt viscosity at 00 ° C, the polyester resin (J) is the product of the tensile breaking strength and the tensile breaking elongation, and the polyester resin (K) is the melt viscosity at 200 ° C and the product of the tensile breaking elongation and the tensile breaking elongation. Does not meet the claim. Polyester resin (K)
Was used as a raw material for producing the polyester resin composition described later.

[0059]

[Table 1]

The abbreviations in the table are as follows. TPA: terephthalic acid, NDCA: naphthalenedicarboxylic acid, IPA: isophthalic acid, AA: adipic acid, DI
A: hydrogenated dimer acid, DDA: dodecanedicarboxylic acid,
BD: 1,4-butanediol, EG: ethylene glycol, DID: hydrogenated dimer diol, PTG100
0: polytetramethylene glycol (number average molecular weight 10
00), PTG2000: polytetramethylene glycol (number average molecular weight 2000), NPG: neopentyl glycol

Production Example of Polyester Resin Composition A polyester resin composition (M) was prepared by uniformly mixing 76 parts by weight of a polyester resin (A), 6 parts by weight of antimony trioxide as a flame retardant and 18 parts by weight of polydibromostyrene. It was obtained by melt-kneading at a die temperature of 170 ° C. using a twin-screw extruder. The polyester resin compositions (N) to (S) were prepared in the same manner as the polyester resin composition (M). Table 2 shows each composition and physical property values. Here, the polyester resin compositions (M) to (Q) satisfy the scope of the claims, but the polyester resin composition (R) is the present patent in terms of the type of polyester resin and the product of tensile breaking strength and tensile breaking elongation. The polyester resin composition (S) does not satisfy the scope of the present invention, and the polyester resin composition (S) does not satisfy the scope of the present invention in the compounding ratio of the polyester resin and the product of the tensile breaking strength and the tensile breaking elongation.

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[Table 2]

As the molding resin, 10 kinds of polyesters (A) to (J) and dimer acid type polyamide are melted at 200 ° C., and a low pressure (˜300 N / cm ² ) injection molding applicator “WS102 / M” is manufactured by Nordson.
X3006 "was used for injection molding. The material to be molded is 20 mm x with two PVC lead wires soldered
15mm circuit board, internal size 25mm × 20mm × 5m
After the molding was performed using the aluminum mold for m of m, the time required for the molded product to be released from the mold without shape loss (mold release time), the molding state on the circuit board was observed. Also, the substrate is 100H at 80 ° C x 95% RH.
It was left to stand and the retention rate of the circuit resistance was measured. It is shown that the larger the retention rate is, the more suitable it is as an insulating material for electric / electronic parts. Moreover, each resin sample was subjected to a pressure cooker test (121 ° C., 0.2 MPa, 100 Hr),
The retention rate of melt viscosity was determined. The smaller the retention rate, the poorer the hydrolyzability of the polyester resin, and the longer-term durability tends to decrease. In addition, the thermal cycle test (-40 ℃
The appearance of the molded product after ˜80 ° C. 20 times) was observed. The results are summarized in Table 3.

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[Table 3]

Further, the polyester resin composition (M)
For (S), make a molded product in the same manner as above,
The mold release time, the molding workability, the appearance of the molded product, the circuit resistance retention rate, the melt viscosity retention rate, and the appearance after the cooling / heating cycle were observed. The results are summarized in Table 4.

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[Table 4]

As shown in Tables 1 and 3, in the case where the polyester resins (A) to (H) satisfying the claims are used, the characteristics of the molded products were all good, but the claims In the case of using the polyester resins (I) and (J) and the polyamide resin which do not satisfy the above range, the characteristics of the molded product are significantly deteriorated. Further, as shown in Table 2 and Table 4, in the case of using the polyester resin compositions (M) to (Q) satisfying the claims, the characteristics of the molded products were all good, but In the case of using the polyester resin compositions (R) and (S) which do not satisfy the scope of the claims, the characteristics of the molded product are significantly deteriorated.

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INDUSTRIAL APPLICABILITY The polyester resin and resin composition of the present invention can provide materials sufficiently satisfying various performances for molding electric and electronic parts having complicated shapes, such as automobiles, communications and computers. It is useful as a molded product of various connectors for home electric appliances, harnesses or electronic parts, switches having a printed circuit board, and sensors.

Continued front page    F-term (reference) 4F071 AA45 AA80 AA84 AA86 AA88                       AF15Y AH12 BB05 BC07                 4J002 CF061 CF081 EJ016 EJ036                       EJ046 EV066 EV076 EW066                       EW086 EW146 FD076 GQ00                 4J029 AA03 AB01 AC01 AC02 AD01                       AD06 AD07 AE18 BA01 BA02                       BA03 BA04 BA05 BA07 BA08                       BA10 BD05A BD06A BF09                       BF10 BF25 CA02 CA06 CB06A                       CC05A CD03 GA22 HA01                       HB01 HB02 KD07 KE02 KE03                 4M109 AA01 CA21 EA12 EE03

Claims (14)

[Claims] 1. The melt viscosity at 200 ° C. is 5 to 1000 d.
Pa · s or less, and the product a × b is 500 or more when the tensile breaking strength of the film-shaped molded product is a (N / mm ² ) and the tensile breaking elongation is b (%). A characteristic saturated polyester resin for molding. 2. The glass transition temperature is −10 ° C. or lower,
And a melting point of 70 to 200 ° C., a saturated polyester resin for molding. 3. A polyester having an ester group concentration of 100.
Saturated polyester resin for molding, which is 0 to 8000 equivalent / 10 ⁶ g. 4. A saturated polyester resin for molding, wherein 2 mol% or more of the diol component of the polyester is polyalkylene glycol when the total amount of the diol component of the polyester is 100 mol%. 5. The saturated polyester resin for molding according to claim 4, wherein the polyalkylene glycol is polytetramethylene glycol having a number average molecular weight of 400 to 10,000. 6. When the total amount of the diol component of the polyester is 100 mol%, 2 mol% or more of the diol component of the polyester is an aliphatic and / or alicyclic glycol having 10 or more carbon atoms. Saturated polyester resin for molding. 7. When the total amount of the dicarboxylic acid component of the polyester is 100 mol%, 2 mol% or more of the dicarboxylic acid component of the polyester is an aliphatic and / or alicyclic dicarboxylic acid having 10 or more carbon atoms. A saturated polyester resin for molding, which is characterized by that. 8. When the total amount of the dicarboxylic acid component and the diol component of the polyester is 100 mol%, 60 mol% or more of the dicarboxylic acid component is terephthalic acid and / or naphthalene dicarboxylic acid, and the diol component. 40 mol% or more of it is 1,4-butanediol and / or ethylene glycol, and the saturated polyester resin for molding according to any one of claims 1 to 7, wherein 9. A polyester resin composition for molding, characterized by comprising 50% by weight or more of the saturated polyester resin according to claim 1. 10. A polyester resin composition for molding, comprising the saturated polyester resin according to any one of claims 1 to 8 and an antioxidant. 11. 100 hours, 121 ° C., 0.2 MPa
The retention rate of the melt viscosity after the heat treatment test is 70% or more of the melt viscosity before the heat treatment test is carried out in the polyester resin composition for molding. 12. The melt viscosity at 200 ° C. is 5 to 1000.
dPa · s, and the product a × b is 500 or more when the tensile breaking strength of the film-shaped molded product is a (N / mm ² ) and the tensile breaking elongation is b (%). A polyester resin composition for molding. 13. A molded product using the saturated polyester resin for molding according to claim 1. 14. A molded product using the polyester resin composition for molding according to claim 9.