JPS6140354A - Resin composition - Google Patents

Abstract

PURPOSE:To prepare a composition which can be molded at a high mold temperature with little formation of burr, by compounding a thermoplastic polyester with a polycarbodiimide compound and Na or K salt of a specific organic monocarboxylic acid. CONSTITUTION:(A) 100pts.(wt.) of a thermoplastic polyester is compounded with (B) 0.1-5pts. of a polycarbodiimide compound, (C) 0.01-3pts. of solium salt or pottassium salt of a 2-32C organic monocarboxylic acid and (D) 0-200pts. of a filler. The component A is polyethylene terephthalate or polybutylene terephthalate, and the component B is preferably an aliphatic polycarbodiimide compound derived from an aliphatic diisocyanate. The component C is a salt of acetic acid, propionic acid, caproic acid, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin composition, and more particularly, to a thermoplastic polyester resin composition that generates extremely little flaking during molding.

<Prior art> Thermoplastic polyesters, represented by polyethylene terephthalate and polybutylene terephthalate, are widely used as fibers, films, plastics, etc. due to their excellent chemical and mechanical properties. It has come to be used in large quantities in the form of equipment parts, automobile interior and exterior parts, and other molded products.

However, the shapes required for these molded products these days reflect social needs such as higher functionality, lighter weight, and resource conservation.
The trend is for products to become more complex, thinner, and smaller than ever before. In order to provide molded products that meet these requirements, thermoplastic polyester as a molding material must be
Before cooling and solidifying in the mold, it is necessary to allow the resin to flow sufficiently to uniformly fill the thin-walled portions and tip portions. Usually, as a countermeasure to this, the fluidity of the resin is improved by draining water or passing heated oil into the mold, or by heating the mold to 80° C. or higher with an electric heater.

Particularly when the thermoplastic polyester is polyethylene terephthalate, molding is generally carried out by heating the mold to a temperature of 120° C. or higher in order to promote crystallization. However, although the fluidity does improve when molding at a higher mold temperature, the fluidity becomes too good and a phenomenon in which the resin flows out along the parting line of the mold, ie, so-called flashing, tends to occur.

Parrying of molded products can be removed by post-finishing, but depending on the shape of the product, it requires an extremely large amount of labor.
Since it also causes a significant decrease in product value, improvement is desired.

<Object of the invention> The present invention was made against the background of the above-mentioned circumstances, and
The purpose is to obtain a thermoplastic polyester resin composition that causes less flaking even when molded at high mold temperatures.

<Structure of the Invention> In order to understand the influencing factors on the fluidity of thermoplastic polyester in a mold, the present inventor tested the relationship between various mold temperatures, molded product wall thicknesses, and flow lengths. At the same time, we also examined the effects of additives, and found that only when a specific polycarbodiimide compound and a specific organic carboxylate were blended into thermoplastic polyester, the fluidity of thin-walled parts when molded at high mold temperatures was reduced. The present invention was achieved by discovering a unique phenomenon in which the occurrence of paris can be suppressed without greatly reducing the fluidity of the resin during molding, which is extremely lower than the fluidity of thick-walled parts. .

That is, the resin composition of the present invention contains (A) per 100 parts by weight of thermoplastic polyester, ('B) 0.1 to 5 parts by weight of a polycarbodiimide compound, and (C) an organic monocarboxylic acid having 2 to 32 carbon atoms. 0 sodium or potassium salts of
．． 1 to 3 parts by weight of (D) filler, and 0 to 200 parts by weight of filler (D).

In the present invention, the thermoplastic polyester used as component (A) uses terephthalic acid or its ester-forming derivative as the acid component, and has 2 to 2 carbon atoms as the glycol component.
The main targets are linear saturated polyesters obtained using No. 10 glycols or their ester-forming derivatives, such as polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate (polybutylene terephthalate), and polyhexamethylene ethylene terephthalate. , polycyclohexane 1,4-dimethylol terephthalate, polyneopentyl terephthalate, and the like. Among these, polynyletine terephthalate and polybutylene terephthalate are particularly preferred.

These thermoplastic polyesters may be used alone or as a mixture of two or more.

Other polyesters may also be used, such as those in which part of the terephthalic acid component or the glycol component having 2 to 10 carbon atoms is replaced with another copolymer component as the acid component. Such copolymerization components include, for example, isophthalic acid, phthalic acid,
Tetrabromophthalic acid.

Halogen-substituted phthalic acids such as tetrabromterephthalic acid; alkyl-substituted phthalic acids such as methylterephthalic acid and methylisophthalic acid; such as 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, and 1,5-naphthalene dicarboxylic acid Naphthalene dicarboxylic acids;
4,4'-diphenyldicarboxylic acid, 3.4'
-Diphenyldicarboxylic acids such as diphenyldicarboxylic acid: 4.4'-Aromatic dicarboxylic acids such as diphenoxyethanedicarboxylic acid;fats such as succinic acid, adipic acid, sebacic acid, azelaic acid, decadicarboxylic acid, cyclohexanedicarboxylic acid, etc. and alicyclic dicarboxylic acids; aliphatic diols such as nitrimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, 1,4-cyclohexane dimetatool, etc.; dihydroxybenzenes such as hydroquinone, resorcinol, etc. ; Bisphenols such as 2,2-bis(4-hydroxyphenyl)propane and bis(4-hydroxyphenyl)sulfone; Aromatic diols such as ether diol obtained from bisphenols and glycols such as ethylene glycol; Polyoxytetramethylene glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, etc.: Oxycarboxylic acids such as ε-oxycabumeronic acid, hydroxybenzoic acid, hydroxyethoxybenzoic acid, etc. . One or more of these copolymerization components can be used, and the proportion thereof is 20 mol% or less, particularly 10 mol% or less, based on the total dicarboxylic acid (half of the oxycarboxylic acid is calculated as carboxylic acid). It is preferable.

Additionally, these thermoplastic polyesters contain branching components such as tricarballylic acid and trimellisic acid.

Trifunctional acids such as trimellitic acid or tetrafunctional acids such as pyromellitic acid having ester type properties and/or glycerin, trimethylolpropane.

1.0 mol% or less of alcohol having trifunctional or tetrafunctional ester type performance such as pentaerythritol,
Preferably 0.5 mol% or less, more preferably 0.3 mol% or less may be copolymerized.

In addition, the intrinsic viscosity of the thermoplastic polyester used here, especially polyethylene terephthalate, is 0.35 or more, more 0.45 or more, especially 0.50 or more, when measured at 35 ° C. using orthochlorophenol solvent. It is preferable.

The above-mentioned thermoplastic polyester can be produced by a conventional production method, such as a melt polymerization reaction or a method combining this with an in-phase polymerization reaction.

In the present invention, the polycarbodiimide compound used as component (B) is a polymer compound having two or more carbodiimide groups (-N=C=N-) in the molecule, such as poly(4,4'-diphenylmethanecarbodiimide), Poly(3,3'-dimethyl-4,4'-biphenylmethanecarbodiimide), poly(tolylcarbodiimide),
Poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,ihexamethylenecarbodiimide) Poly(1,4-tetramethylenecarbodiimide), poly(4,4'-methylenebismicrohexylcarbodiimide), poly(1,3 and 1
．． 4-cyclohexylenecarbodiimide), poly(1,
3-diisopropylphenylenecarpodiimide), poly(1-methyl-3,5-diimpropylphenylenecarpodiimide), poly(1,3',5-t-ethylphenylenecarbodiimide), poly(triisopropylphenylenecarpodiimide) ), etc.

The polycarbodiimide compound of the present invention has an average molecular weight of 1.0.
If the average molecular weight is less than i, ooo, it will volatilize during crosstalk, making it difficult to mix with other components.

These polycarbodiimide compounds are usually derived from the corresponding diisocyanate compounds and can be produced, for example, by heating the diisocyanate in the presence or absence of a solvent.

These polycarbodiimides can be produced without catalysts, but in the absence of catalysts they can be produced at high temperatures (approximately 300 °C).
reaction, which can sometimes produce large amounts of by-products and colored products.

Typical polycarbodiimides are described in U.S. Pat.
78, 2,663,737 and 3,755,242
and Numonable, J, ovry, Chen+, 2
7.3851 (1962) by heating isocyanates in the presence of catalysts such as the phosphorus-containing catalysts described in J.D. 7.3851 (1962).

Campbell et al., J, AI+er, chem,
S.O.C.

84, 3678 (1962) is a preferred catalyst; a particularly preferred catalyst is 1-ethyl-
3-methyl-3-phosphorine-1-oxide is mentioned.

Among these polycarbodiimide compounds, aliphatic polycarbodiimide compounds derived from aliphatic diisocyanates are particularly effective during molding due to their synergistic action with component (C), a metal salt of a specific organic carboxylic acid. This is preferable because the effect of preventing the occurrence of paris is significantly exhibited.

The amount of the polycarbodiimide compound added is 0.1 to 5 parts by weight, preferably 0.2 to 2 parts by weight, per 100 parts by weight of the thermoplastic polyester.

If the amount added is less than 0.1 part by weight, the prevention of flaking, which is the objective of the present invention, will not be sufficiently achieved.

On the other hand, if the amount is more than 5 parts by weight, the fluidity of the resin composition will deteriorate, causing a practical problem.

The sodium salt or potassium salt of organic monocarboxylic acid as component (C) used in the present invention has the formula R-C
It is a salt of an organic monocarboxylic acid represented by OOH. Here, R is a hydrocarbon group having 1 to 31 carbon atoms, preferably 19 to 31 carbon atoms, and includes, for example, an alkyl group, a cyclic hydrocarbon group having a cyclo ring or a benzene ring, and an aralkyl group. Among these, R is preferably an alkyl group or an aryl group.

Examples of the sodium or potassium salts of organic monocarboxylic acids include acetic acid, propionic acid, caproic acid, caprylic acid, lauric acid, myridic acid, balmitic acid, stearic acid, behenic acid, alaxic acid, lignoceric acid, and cerotic acid.

Examples include sodium or potassium salts of saturated fatty acids such as montanic acid, melisic acid, and the like.

When these organic monocarboxylic acid salts are added alone to thermoplastic polyesters, they do not contribute to preventing moldings from forming, but when used in combination with the polycarbodiimide component (B), they exhibit a remarkable effect of preventing flakes.

The amount of sodium salt or potassium salt of organic monocarboxylic acid is 0 per 100 parts by weight of thermoplastic polyester.
．． The amount is preferably 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight.

If the blending amount is less than 0.01 part by weight, the anti-corrosion effect, which is the object of the present invention, will not be sufficiently achieved.

On the other hand, if more than 3 parts by weight is used, the fluidity of the resin composition will be impaired and the mechanical strength of the molded product will also be reduced, which is not preferred.

In the present invention, glass fibers and asbestos are used as component (D) fillers if desired.

Fibrous materials such as carbon fiber, aromatic polyamide Ti&fiber, potassium titanate fiber, steel fiber, ceramic fiber, poron whisker fiber, etc., mica.

Silica, talc, calcium carbonate, glass peas.

Examples include inorganic fillers in the form of a single powder or a plate, such as glass flakes, clay, and wollastonite.

These fillers are usually used as reinforcing material 1 surface modification material.
Alternatively, glass WiA is used as a filler for the purpose of modifying electrical, thermal, and other properties.
H is commonly used as a reinforcing filler.

The glass fiber is not particularly limited as long as it can generally be used for reinforcing resins. For example, it can be selected from long fiber type (glass roving), yr1 fibrous chopped strand, milled fiber, etc. Further, the glass fibers may be treated with a sizing agent (eg, polyvinyl acetate, polyester sizing agent, etc.), a coupling agent (eg, silane compound, borane compound, etc.), or other surface treatment agent. Furthermore, it may be coated with a resin such as a thermoplastic resin or a thermosetting resin. Usually long fiber type glass! fiIft is used by being cut into a desired length before or after blending with the resin, and this mode of use is also useful in the present invention.

Any compounding method can be used to obtain the resin compositions of the present invention. Generally, it is preferable to disperse these components more uniformly, and there are methods of homogenizing all or part of them simultaneously or separately using a mixer such as a blender, kneader, roll, extruder, etc., and methods of homogenizing the mixed components. Mix some of the ingredients simultaneously or separately using a blender, kneader, roll, extruder, etc., and then add the remaining ingredients.
A method of mixing and homogenizing using these mixers or extruders can be used.

The most common method is to homogenize a pre-triblended composition by melt-kneading it in a heated extruder.
This is a method in which the material is extruded into a nail shape, then cut into desired lengths and granulated. The resin composition prepared in this manner is usually sufficiently dried and kept in a dry state before being charged into a molding machine hopper and subjected to molding. Other methods include, for example, a method in which other components are added or mixed during the production of the thermoplastic polyester, before the polycondensation, after the polycondensation, or during the polycondensation.

Various additives can be added to the resin composition of the present invention for the purpose of further improving other properties.

For example, for the purpose of improving flame retardancy, decabromo biphenyl ether, octabromo biphenyl ether, hexabromo biphenyl ether, halogenated polycarbonate oligomers (for example, polycarbonate oligomers produced using brominated bisphenol A as a raw material), halogenated epoxy compounds, Halogen-containing compounds such as halogenated polystyrene oligomers (e.g. oligomers of tribromustyrene); red phosphorus, phosphorus compounds; flame retardants such as phosphorous mononitrogen compounds such as phosphonic acid amides; flame retardants such as antimony trioxide, zinc borate, etc. Auxiliary agents and the like can be added in the desired amount.

Furthermore, for the purpose of improving heat resistance, antioxidants or heat stabilizers such as hindered phenol compounds and Ta yellow gold compounds can be added.

Furthermore, various epoxy compounds can be added for the purpose of improving heat stability, hydrolysis resistance, etc.

For example, bisphenol A-type epoxy compounds obtained by reacting sulfinol A and epichlorohydrin, aliphatic glycidyl ethers obtained by reacting various glycols or glycerol with epichlorohydrin, novolac-type epoxy compounds obtained from novolac resins and epichlorohydrin, alicyclic compounds. and organic carboxylic acid glycidyl esters obtained by reacting various di- or polycarboxylic acids with epichlorohydrin or glycidol.

Among these, bisphenol type epoxy compounds, silyglycidyl ether of low molecular weight polyethylene glycol, and terephthalic acid diglycidyl ester are particularly preferred.

Other additives include UV absorbers and 9 colorants.

Examples include lubricants, antistatic agents, foaming agents, and the like.

In addition, other thermoplastic resins such as styrene resin, acrylic resin, polyethylene, polypropylene,
Fluororesin, polyamide resin, polycarbonate resin,
Polysulfone, etc.; thermosetting resins such as phenolic resins,
In addition to melamine resins, unsaturated polyester resins, silicone resins, etc., soft thermoplastic resins such as ethylene-vinyl acetate copolymers, polyester elastomers, etc. may be added.

<Effects of the Invention> The resin composition of the present invention can be easily molded by a normal method using a general molding machine for thermoplastic resins. Furthermore, due to the synergistic effect of the polycarbodiimide and the specific organic monocarboxylic acid metal salt, it is possible to obtain a molded product with extremely little occurrence of flash even when molded at a high mold temperature.

<Examples> The present invention will be described in detail below with reference to Examples. In addition, the intrinsic viscosity of the thermoplastic polyester described in the examples is a value measured at 35° C. in an ortho-90-day phenol solution. Furthermore, parts refer to parts by weight.

Various properties in the examples were measured by the following methods.

(1) When the resin composition is molded in a side gate mold as shown in Paris index diagram 1, the resin is completely filled into the cavity B which is dug in the direction perpendicular to the gate with respect to the cavities A and A. The Paris index was defined as the minimum flow length of 1150 for the resin flowing into the cavity C section when the resin was allowed to flow.

What the Paris index means is B of thickness o, 5a111
The purpose is to compare the fluidity of the C cavity of 0.05 #1llI, which corresponds to the thickness of the normal Paris, with the fluidity of the C cavity. The length of fluidity that can be achieved is small, that is, the Paris index is small. In fact, it has been confirmed that the smaller the Paris index, the less Paris occurs.

(2) Particle occurrence level When a 12aR square plate with a thickness of 2 mm was molded using a side gate as shown in chart-2, the occurrence of parf on the mold parting surface was classified and displayed in the following four stages.

×: Occurrence of cracks is observed all around the corner plate.

△: Although the degree is small, occurrence of paris is observed all around.

O: Some occurrence of cracks is observed near the gate.

◎: No burrs observed.

Examples 1-6 and Comparative Examples 1-5 100 parts of polyethylene terephthalate with an intrinsic viscosity of 0.65 dried at 120°C for 4 hours, chopped strand glass fiber with a length of 3M @40 parts, 2 parts of talc, 2 tables −
After uniformly mixing the polycarbodiimide shown in 1 and various organic monocarboxylic acid salts in a tumbler in the ratio shown in Table 1, the mixture was mixed with a screw system 65III! While drawing a vacuum using an Rφ vented extruder, the cylinder temperature was increased to 2.
The mixture was melted and mixed at 15° C., and the thread coming out of the die was cooled and cut to obtain pellets for molding.

These pellets were used in a 5-ounce injection molding machine at a cylinder temperature of 210°C and an injection pressure of 800 kg/ci.

Mold temperature 140℃, cooling time 25 seconds and total cycle 4
Thirty shots each were injection molded using the molds shown in Figures 1 and 2 under conditions of 0 seconds.

The resulting injection molded product was measured for Paris index and degree of Paris occurrence.

The results are shown in Table-1.

(The following is a blank space) From the results in Table 1, it is clear that by adding polycarbodiimide and an organic monocarboxylic acid metal salt in combination, the Paris index can be reduced and the degree of Paris generation can be improved.

If either one of the polycarbodiimide organic monocarboxylate salts is lacking, the effect of preventing Paris cannot be obtained.

Example 7 and Comparative Examples 8 to 10 100 parts of polybutylene terephthalate with an intrinsic viscosity of 0.90 dried at 120°C for 3 hours was uniformly mixed with the polycarbodiimide and organic monocarboxylic acid salt shown in Table 2 in advance in a tumbler. After that, it was extruded under the same conditions as in Example 1 to obtain pellets for molding.

Further, the pellets were used in a 5-ounce injection molding machine at a cylinder temperature of 260°C and an injection pressure of 800 kg/crI.

Mold temperature 100℃, cooling time 25 seconds and total cycle 4
30 each using the molds shown in Figure-1 and Figure-2 under the condition of 0 seconds.
Shot injection molded.

The resulting injection molded product was measured for Paris index and degree of occurrence of Paris.

The results are shown in Table-2.

(Margins below) Table 2 Note 2) Molded product (9) Average value of shots As is clear from the results of Cloth-2, by adding organic monocarbon MjlJ and polycarbodiimide in combination, the paris index can be reduced and paris can be prevented. The effect is expressed. .

Example 8 100 parts of polyethylene terephthalate with an intrinsic viscosity of 0.58 dried at 130°C for 4 hours, 18 parts of chopped glass with a length of 3, and 36 parts of talc (PKN manufactured by Hayashi Kasei)
part, sodium montanate (used in Example 1)
．． 4 parts: 1.2 parts of poly(1,4-cyclohexylenecarbodiimide), 12 parts of decabromodiphenyl ether, and 7 parts of antimony trioxide were uniformly mixed in advance and extruded and molded under the same conditions as in Example 1. The Paris index of this product was 0.11, and the Paris occurrence degree was ◎.

[Brief explanation of the drawing]

1 and 2 are perspective views of the side gate mold used in the present invention to measure the Paris index and degree of occurrence of Paris;
: C is cavity, 1 is gate. Figure 1 8z diagram

Claims (1)

[Claims] 1. (A) per 100 parts by weight of thermoplastic polyester (B) 0.1 to 5 parts by weight of a polycarbodiimide compound (C) Sodium or potassium salt of an organic monocarboxylic acid having 2 to 32 carbon atoms A resin composition comprising 0.01 to 3 parts by weight of a salt and 0 to 200 parts by weight of a filler (D).