JPH02209941A - Vinyl chloride resin composition for powder molding - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in fluidity of powder, moldability, odor, heat resistance and cold resistance and suitable for an automobile-interior trim material by dry blending a vinyl chloride-based resin with a specified trimellitate-based plasticizer. CONSTITUTION:An objective composition obtained by blending a vinyl chloride- based resin with a trimellitate-based plasticizer in which unreacted alcohols are reduced to <=500ppm, preferably <=300ppm represented by the formula [R is alkyl having >=85mol% straight chain ratio, 5-55%, preferably 10-45% ratio of 1-7C and <=10%, preferably <=6% ratio of >=9C] and prepared by using higher alcohols produced by hydrogenation of natural fats and oils or hydrolysis of an aluminum alkoxide as the raw material.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a powder molding vinyl chloride resin composition suitable for automobile interior materials.

<Prior Art> The present invention relates to a powder-based composition for powder rotary molding or powder slush molding suitable for covering materials such as crash pads, armrests, headrests, consoles, meter covers, or door trims as automobile interior materials. .

In recent years, there has been a growing demand for such covering materials used as automobile interior materials that are lightweight, have an excellent soft feel, and are provided with leather grain patterns, stitch patterns, etc. that give a classy appearance.

Conventionally, these covering materials include soft sheet vacuum molded products mainly made of vinyl chloride resin and ABS resin, and sol rotary molded or slush molded products made mainly of paste vinyl chloride resin and plasticizer ( (hereinafter referred to as sol molded products).

However, although vacuum-formed products have achieved their goal in terms of weight reduction, they lack a soft feel and can only be produced with a hard feel.Furthermore, they cannot be manufactured with complicated leather textures or stitched patterns that give a sense of luxury. It is difficult to shape something with shape.

Further, vacuum-formed products have the disadvantage that they have large residual strain during molding and are prone to cracking during long-term use.

On the other hand, although sol-molded products have a soft feel, their gelation temperature is low, so they melt quickly in the mold, causing phenomena such as flow marks, lips, or sol stringiness.

As a result, they suffer from drawbacks such as a lack of smoothness on the back surface, too much time required to discharge the sol from the mold, and a thick covering material.

In addition, in the case of sol, there are other problems, such as the difficulty of cleaning tanks and piping when changing colors, and the viscosity change caused by oral administration, which makes it difficult to store for long periods of time.

Recently, powder molding methods have been attracting attention in order to solve these drawbacks and problems.

Powder molding methods generally include fluidized dipping, electrostatic coating, powder spraying, powder rotary molding, and powder slush molding, but powder rotary molding and powder molding are particularly used for covering materials for automobile interior materials. Slash molding method is suitable.

180℃ for powder rotary molding method or powder flash molding method
The powder is melted onto the inside of the mold by rotating, rocking, or spraying the mold and powder supply box, which are at a temperature above 100 degrees, and automatically or forcefully collects the unwelded powder into the powder supply box. This is the way to do it.

(Japanese Unexamined Patent Publication No. 58-182507) In addition, the heating method of the mold used in the powder molding method includes a gas heating furnace method, a heat medium oil circulation method, a method of immersion in heat medium oil or thermal fluidized sand, or There are high frequency induction heating methods. (Sumitomo Chemical Journal 1985-I, pp. 84-91) A powder composition is made by dry-breading vinyl chloride, plasticizers, stabilizers, pigments, etc. using a blender with a heating jacket or a high-speed rotating mixer. It is well known to create

<Problems to be Solved by the Invention> The powder resin composition used in the powder molding method must have excellent powder fluidity and moldability. In particular, as automobiles become larger and more sophisticated, the shapes of crash pads, meter hoods, etc. have become larger and more complex, so it is important to improve the powder fluidity and moldability of powder resin compositions. is desired.

In order to improve powder fluidity and moldability, it is well known that inorganic fillers such as fine particles of vinyl chloride resin and fine particles of calcium carbonate and silica are added during the cooling stage after completion of dry breading.

(Rubber Digest Vol @ 14 eArashi 8 No. 82
~40 pages and polyvinyl chloride - its chemistry and industry - I No. 8
pp. 67-870, 1968 and Special Publication 1987-1575
).

However, this is not necessarily sufficient to meet the high quality requirements of the target molded product.

Furthermore, the powder resin composition used in the powder molding method must have little odor.

180 for powder rotary molding or powder slush molding
After welding the powdered resin composition to a mold that is at a temperature of over °C, it is heated again to melt it, and after cooling to about 70 °C, an operator removes the molded sheet from the mold. A strong odor from the resin composition, especially the plasticizer, which is one of the constituents of the composition, not only worsens the working environment and causes discomfort to workers engaged in the molding process, but also causes damage to automobile interior materials after molding. If the odor remains, it will reduce the value of the product and is undesirable.

Furthermore, in recent years, the area of the windshield has become larger due to the increasing luxury of automobiles, changes in design, and lower air resistance, and the angle of the windshield has become nearly parallel to the crash pad and meter hood. The surface temperature of materials has risen more than ever before, and the required level of heat resistance has become higher than ever.

Furthermore, when automobile interior materials such as crash pads and meter hoods are used in cold regions, if the surface of the covering material breaks or cracks due to falling objects or impact, the product value decreases and is not desirable. Covering materials for automobile interior materials such as crash pads and meter hoods molded from resin compositions are also required to have cold resistance.

Trimelitate plasticizers are preferred as plasticizers used in powdered resin compositions to improve the heat resistance of automotive interior covering materials, as they evaporate during high-temperature heating and are less likely to migrate to the urethane foam layer lining. It's starting to look like this.

However, trimellitate plasticizers generally have poor absorption into vinyl chloride resin particles, and for this reason, powder resin compositions produced using trimellitate plasticizers have a high concentration of plasticizer on the surface of the vinyl chloride resin particles, and Because of the stickiness, even if fine particles of vinyl chloride resin or fine particles of inorganic filler are added in the cooling stage after completion of dry breading, the effect of improving powder fluidity and moldability is insufficient.

Furthermore, since automobile interior materials manufactured using trimellitate plasticizers generally have poor sensitivity resistance, it is necessary to devise ways to improve cold resistance.

Means for Solving the Problems> The above-mentioned requirements, namely, improvement of powder fluidity and moldability of powdered resin compositions, reduction of odor, and heat resistance and cold resistance of automobile interior materials molded using powdered resin compositions. In order to simultaneously achieve the reduction of odor and odor, the present inventors conducted intensive studies on trimellitate plasticizers used in powdered resin compositions.

As a result, when the chain length of the alkyl group of the trimellitate plasticizer is long, the heat resistance of the molded product is good, but the powder fluidity and moldability deteriorate. If the straight chain ratio of the alkyl group of the trimellitate plasticizer decreases, the powder fluidity and moldability will improve, but the heat resistance of the molded product will deteriorate. Powder resin compositions using trimellitate plasticizers with chain length distribution of alkyl groups within a certain range and linear chain ratio of 86 mol% or more, preferably 90 mol% or more, have poor powder flowability. It has been found that moldability is good, and the molded product has good heat resistance and cold resistance.

Furthermore, trimellitate plasticizers produced using higher alcohols synthesized via aldehydes as intermediates such as the oxo method have a pungent odor, and powdered resin compositions produced using Mukuro trimellitate plasticizers are irritating during molding. The smell deteriorates the working environment, and the product also has a irritating odor.Also, if a large amount of unreacted alcohol remains in the trimellitate plasticizer, powdered resin compositions manufactured using the trimellitate plasticizer may It was found that an oil odor occurs during molding, deteriorating the working environment, and that the oil odor remains in the product. Powdered resin compositions manufactured using trimellitate plasticizers with reduced odor have no irritating or oily odors during molding, and no irritating or oily odors remain in the molded automobile interior materials. Heading, the invention was completed.

That is, the present invention provides a powder composition obtained by dry-blending a vinyl chloride resin with a plasticizer, stabilizer, and other pigments, fillers, blowing agents, auxiliary agents, etc., which are added as necessary.
The vinyl chloride resin has the formula (1) (However, in the formula (1), R has a linear chain rate of 85 mol% or more, the proportion of carbon atoms of 7 or less is 5 to 55 mol%, and the proportion of carbon atoms of 8 is 45 ~96 mol% and the proportion of carbon atoms of 9 or more is 10 mol% or less, which may be the same or different alkyl groups), and hydrogenation of natural oils and fats or hydrolysis of aluminum alkoxide Using the higher alcohol produced by
The present invention relates to a vinyl chloride resin composition for powder molding, which is characterized in that it contains a trimellitate plasticizer in a reduced amount as follows.

The chain length distribution of the trimellitate plasticizer represented by the formula (1) used in the present invention will be described in detail.

As the alkyl group in which R has 7 or less carbon atoms, preferable examples include alkyl groups having 7 and 6 carbon atoms, and the content thereof is 5 to 6 carbon atoms.
It is 56 mol%, preferably 10 to 45 mol%. If this ratio is less than 5 mol %, the powder fluidity and moldability of the powder resin composition will deteriorate, which is not preferable. Moreover, if it exceeds 55 mol%, the heat resistance of the molded product will be poor (which is not preferable).

The content of an alkyl group in which R has 8 carbon atoms is 45 to 96 mol%
, preferably 55 to 90 mol%. This ratio is 45
If it is less than mol %, the heat resistance of the molded product will deteriorate, which is undesirable, and if it exceeds 95 mol %, the powder fluidity and moldability of the powder resin composition will deteriorate, which is undesirable.

The content of the alkyl group in which R has 9 or more carbon atoms is preferably as small as possible, and is 10 mol% or less, preferably 6 mol% or less. If this ratio exceeds 10 mol %, the powder fluidity and moldability of the powder resin composition will deteriorate, which is not preferable.

Further, the linear chain ratio of R is 85 mol% or more, preferably 90 mol% or more. If the linear chain ratio is less than 85 mol %, the cold resistance of the molded article will decrease, which is not preferable. Here, the linear chain ratio refers to the proportion of linear alkyl groups such as normal-octyl, normal-heptyl, and normal-hexyl among all the alkyl groups (R). Incidentally, examples of branched alkyl groups that are not linear include iso-octyl, iso-heptyl, iso-hexyl and 2-ethyl-hexyl.

Next, odor reduction of the trimellitate plasticizer used in the present invention will be described in detail.

In order to remove the pungent aldehyde odor, it is important to select a higher alcohol with a high linear chain ratio to be used as a raw material for trimellitate plasticizers. Methods for producing higher alcohols with a high linear chain ratio include hydrogenation of natural oils and fats such as coconut oil and palm oil, and the Alfor method, which synthesizes aluminum alkoxide using ethylene as a raw material and hydrolyzes it. , the oxo method, in which olefins are synthesized from ethylene, wax, or normal paraffin by the Ziegler method, and produced through hydrophorylation and hydrogenation. Among these, the oxo method uses aldehyde as an intermediate, so trimellitate plasticizers produced using higher alcohols synthesized by the oxo method have a pungent odor due to slight residual aldehyde, which is undesirable. As a method for producing a higher alcohol with a high linear chain ratio, a method by hydrogenolysis of natural fats and oils and an Alfol method are preferable, and a method by hydrogenolysis of natural oils and fats is particularly preferable because it is cheap and easily available.

Furthermore, in order to reduce the oil odor, it is important to reduce the amount of unreacted raw material alcohol that remains after producing the trimellitate plasticizer. The general method for producing trimellitate plasticizers is to add the above-mentioned higher alcohol to trimellitic anhydride, heat the reaction in the presence of an acidic catalyst and a water entrainer, and then wash the mixture with a dilute aqueous alkaline solution and water in that order. The water entraining agent is removed by distillation at normal pressure, the unreacted alcohol is recovered by distillation under reduced pressure, and the product is purified using activated carbon or the like. However, trimellitate plasticizers produced by the above-mentioned general method usually contain 11,000 pp or more of unreacted alcohol, which causes oily odor and molded products when molding powdered resin compositions using the trimellitate plasticizers. This is undesirable because it causes oil to build up in certain automobile interior materials. On the other hand, after producing by the above-mentioned general method, the amount of unreacted alcohol is reduced to 500 ppm or less, preferably 800 ppm or less, by countercurrently producing it with live steam using a thin film evaporator or the like.
Powdered resin compositions using trimellitate plasticizers reduced to ppm or less have almost no oil odor during molding and are excellent in the working environment.Furthermore, the molded automobile interior materials have almost no unpleasant oils and fats, making the product easier to use. This is preferable in terms of increasing added value.

The amount of the trimellitate plasticizer used in the present invention is not necessarily limited, but it can be used, for example, in a proportion of 80 parts by weight or more and 90 parts by weight or less per 100 parts by weight of the vinyl chloride resin. If the above-mentioned trimellitate plasticizer is used in an amount of 80 parts by weight or less per 100 parts by weight of the vinyl chloride resin, the heat resistance and cold resistance of the molded article will deteriorate, which is disadvantageous. Furthermore, if the trimellitate plasticizer is used in an amount of 90 or more affected parts per 100 parts by weight of the vinyl chloride resin, the powder fluidity and moldability of the powder resin composition will deteriorate, which is not preferable.

In addition, in the present invention, other plasticizers, particularly phthalate ester plasticizers such as diisodecyl phthalate, diisoundecyl phthalate, and dialkyl phthalate whose alkyl group has 9 to 11 carbon atoms, may be added to the trimellitate plasticizer. It is also possible to use them together within a range that does not impair the purpose of the invention.

The vinyl chloride resin used in the present invention includes vinyl chloride polymers or vinyl chloride made by suspension polymerization, bulk polymerization, and emulsion polymerization, and ethylene, propylene, and vinyl acetate that can be copolymerized with vinyl chloride. , copolymers with monomers such as alkyl acrylates and alkyl methacrylates, graft copolymers of vinyl chloride onto copolymers of ethylene and vinyl acetate, and mixtures of two or more of these polymers. However, it is not necessarily limited to this.

A stabilizer can be added to the vinyl chloride resin composition of the present invention.

Stabilizers used in the present invention include zinc, barium,
Examples include metal compounds such as sodium, potassium, calcium, lithium, and tin, such as metal salts of carboxylic acids, and among these, complex salts of zinc and barium are preferably used.

Further, stabilizers such as magnesium oxide, magnesium hydroxide, hydrotalcite compounds, zinc oxide, barium oxide, calcium oxide, barium phosphate, etc. can also be added to these stabilizers. Furthermore, phenolic and thioether antioxidants, hindered amine and phosphite compounds, diketo compounds, salicylic acid esters, ultraviolet absorbers such as benzophenone and benzotriazole, and epoxidized soybean oil and bisphenol A.
It is also possible to use an epoxy compound produced by synthesis of and epichlorohydrin. In particular, it is preferable to use a hydrotalcite compound in combination with a composite salt of zinc and barium, since this improves the heat resistance during urethane lamination.

In addition to plasticizers and stabilizers, pigments, fillers, blowing agents, and various auxiliary agents can be added to the powdered vinyl chloride resin composition of the present invention, if necessary.

Note that 100 layers of vinyl chloride resin in the present invention refers to the total heavy chain of the vinyl chloride resin added before dry breading and the fine particles of vinyl chloride resin added after completion of dry breading.

<Example> 1. Trimelitate plasticizer The manufacturing method and alkyl chain length distribution of higher alcohol, which is the raw material for the trimellitate plasticizer used in the examples and comparative examples of the present invention, and the unreacted amount remaining in the trimellitate plasticizer. Table 1 shows the content of each raw material alcohol.

Here, the content of unreacted raw material alcohol remaining in the trimellitate plasticizer was measured by gas chromatography under the following conditions.

Gas chromatography conditions Apparatus: Shimadzu GC-7A type Color A: PEG-20M Ri0 Mosorb W
10% impregnated glass column I, D, 8tzφxsm Column temperature: 170°C Injector temperature: 250°C Carrier gas: N2 Detector: FID Sample injection jl: 1 microliter Nao, raw material 7 Lecol 5001) 1) mllooop
p.m.

A calibration curve was created using a CHClB solution containing 2000 ppm, and quantification was performed.

\ \ \ 2. Evaluation items and methods The resin composition of the present invention was evaluated for the following items.

(1) Pour 100 ml of the powder flowable powder resin composition into the funnel of a JIS-6721 oyster specific gravity measuring device, pull out the damper, and the time from when the sample begins to fall to when all the samples have finished falling. (number of seconds) was measured. The results of Examples 1 to 8 and the results of Comparative Examples 1 to 8 are shown in Table 2. The shorter the number of seconds, the better the powder fluidity.

(2) Sprinkle the moldable powder resin composition 500F on a nickel electroformed textured plate of size 800m x 800m heated in a heating furnace with an ambient temperature of 800°C to a mold temperature of 220°C, let it adhere for 10 seconds, and then The unmelted powder of the powder resin composition is discharged, and the powder welded grain plate is heated to an ambient temperature of 80°C again.
It was heated and melted for 40 seconds in a heating furnace at 0°C. The average thickness of the molded sheet after cooling was IN. The moldability (breakability) was determined from the weight of this sheet. That is, if the moldability (cutting ability) is poor, the unmelted powder will not be discharged sufficiently and a considerable amount of unmelted powder will remain, resulting in a heavy sheet.

In addition, moldability (breakability) was evaluated based on the condition of the back surface of the molded sheet using the following criteria.

: Uniformly melted with no unmelted parts.

O~△D There are some unmelted parts. (approximately 5% or less of the whole) △: There is a considerable amount of unmelted portion. (approximately 5 to 80
%) ∆~×: There are many unmelted parts, giving a lumpy feel to some parts. (Approximately 80 to 60% of the total): There is a large amount of unmelted parts, giving a lumpy feel to the whole. (50% or more of the total) The results of Examples 1 to 8 and the results of Comparative Examples 1 to 8 are shown in Table 2.

(8) Powdered resin composition No. 51 was placed in a cylindrical can with an odor internal volume of 150 cc, sealed, heated in a heating oven at an ambient temperature of 100°C for 80 minutes, and then opened. Five panelists conducted a sensory test to determine the following: The odor during molding was evaluated using the following criteria.

○: Almost no odor △: There is an odor and it is slightly unpleasant.

×; The odor is strong and unpleasant.

The results of Examples 1 to 8 and the results of Comparative Examples 1 to 8 are shown in Table 2.

(4) Place the molded sheet made in the test in (2) with the textured side facing down in an aluminum support frame with a width of 800w x 8000mm and a thickness of 10m placed on a foam table made of heat-resistant aluminum plate. Next, an NGO content of 80.5% was added to 100 parts by weight of a polyol mixture mainly containing water, triethanolamine, and triethylene cyano in a pre-prepared polyol mainly composed of propylene oxide and ethylene oxide adducts of glycerin. A total of 158j' of a certain polymeric MDI was injected at a rate of 50 parts by weight, foamed, and adhered to the back side of the sheet. The laminated urethane has a thickness of 9 fl and a foam density of 0.16 f.
/d. This urethane bonded sheet is cut to the specified dimensions (
Eight test pieces were placed in a gear oven type heating furnace in a 110°C atmosphere so that they could be taken out every 400 hours, and a heat discoloration test and a heat aging test were conducted for up to 120 hours.

Judgment for heat discoloration test follows gray scale grade.
In addition, the results of the heat aging test were determined by peeling off the molded sheet from the test piece after a predetermined period of time in a 110°C gear oven.
After punching out the sample with JIS 6801 No. 1 dumbbell, it was tested at room temperature (28°C) with a tensile tester at 200 m/mi.
It is expressed as elongation at break (%) when elongated at a constant speed of n. Table 2 shows the results of Examples 1 to 8 and the results of Comparative Examples 1 to B.
Shown below.

(6) Cold resistance The urethane laminated sheet prepared for the heat resistance test in (4) was cut to 1001 fjll x 100 KM, cooled to 1-40°C, and immediately tested using a DuPont falling weight impact tester at 60°C.
A low temperature shock test was performed by dropping a 0y weight from a predetermined height.

Cold resistance was determined by the highest height at which eight test pieces did not crack. Table 2 shows the results of Examples 1 to 8 and Comparative Examples 1 to 8.
Shown below.

Examples 1 to 8, Comparative Examples 1 to 8 Next, examples will be shown, but the present invention is not limited to these.

(1) Details of preparation of resin composition for powder molding Straight vinyl chloride resin with an average degree of polymerization of 800 made using a normal suspension polymerization method in a super constant mixer of FF1201 (Sumitomo Chemical ■■Sumilit 5K-8G) 1 #8 was charged and stirred at a constant rotational speed, and when the resin temperature reached 80°C, a plasticizer and a stabilizer, pigment, and epoxidized soybean oil that had been prepared in advance together with the plasticizer were added and dry breaded.

The types and amounts of plasticizers used are shown in Table 2.

Stabilizers are barium chelate 14f1 zinc oxalate 12f
and perchlorate ion type hydrotalcite compound 2
It is a composite stabilizer consisting of 0F. The pigment is a gray pigment manufactured by Sumika Color, and the amount added is 80f. The epoxidized soybean oil is 0-180P manufactured by Adeka Argus, and the amount added is 8
It is 0F. When the dry bread temperature reaches 122°C, the heating steam is stopped, and after the dry bread is completed, it is switched to water cooling and cooled to a temperature below 50'C. Sumilit ■PXQL] 2001 was uniformly dispersed to obtain a powdered resin composition.

(2) Evaluation Results The obtained powder resin compositions were evaluated for powder fluidity, moldability, odor, heat resistance, and cold resistance using the methods described above, and the results are listed in Table 2.

In Examples 1 to 8, the powder resin compositions had good powder fluidity and moldability, had little odor, and had good heat resistance and cold resistance.

In Comparative Example 1, the powder resin composition had insufficient powder fluidity and moldability, and also had an oily odor due to unreacted alcohol.

Comparative example? The powdered resin composition has a strong irritating odor and oily odor based on aldehyde odor (insufficient).

Although the powder resin composition of Comparative Example 8 has almost no oil odor, it has an irritating odor based on aldehyde odor, and is therefore unsatisfactory. Moreover, the heat resistance and cold resistance of the molded sheet are poor and insufficient.

Claims (1)

[Claims] In a powder resin composition made by dry-breading a vinyl chloride resin with a plasticizer, the vinyl chloride resin has a formula (I) ▲a mathematical formula, a chemical formula, a table, etc.▼(I) (However, (I) In the formula, R has a straight chain ratio of 85 mol% or more, a proportion of carbon atoms of 7 or less is 5 to 55 mol%, a proportion of 8 carbon atoms is 45 to 95 mol%, and a proportion of carbon atoms of 9 or more is 10 The unreacted alcohol is made from a higher alcohol produced by hydrogenation of natural oils or fats or hydrolysis of aluminum alkoxide. A vinyl chloride resin composition for powder molding, characterized in that it contains a trimellitate plasticizer whose content is reduced to 500 ppm or less.